Deslandres table¶

In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions.

Version: v1 · 2026-09-28 · History
Domain-specific #: 8932
Domain group: Natural Sciences
Origin domain: Physics
Subdomains: Molecular Spectroscopy, Vibronic Spectroscopy → Physics

Core Idea¶

Deslandres table is treated here as the recurring cross-domain formal modeling identity summarized by this source-grounded definition: In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions.

In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions. In such a table, the frequencies of the lines seen in an electronic spectrum of a molecule are collected so that the differences in energy between adjacent columns or rows are all the same (within experimental error). Every line seen in the spectrum corresponds to a transition from the lower-lying electronic energy state to an excited electronic state (molecular electronic transition): associated with this, there are corresponding transitions between the vibrational levels of the two states, that give rise to many closely spaced lines.

The intensity of the lines is governed by the Franck–Condon principle. When a Deslandres table is filled correctly, the columns represent the vibrational energy levels of the lower electronic state (v ), while the rows represent those for the upper electronic state (v ' ). Clearly, the difference in energy between two successive rows (columns) must remain constant for any column (row) in the table because this represents the energy difference of two given vibrational levels within the same electronic state.

For Deslandres table, the abstraction is narrower than the article's general subject matter: a positive case must preserve In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions. Retaining only the name, a familiar example, or a downstream effect is insufficient. The specialist roles and tests remain anchored in cross-domain formal modeling, which is why this identity is domain-specific rather than prime.

How would you explain it like I'm…

The Light-Line Sorting Grid

When a molecule soaks up light, it makes a pattern of thin lines, like a barcode. Scientists write the line numbers into a grid, arranged so that the steps from one column to the next, and one row to the next, are always the same size. That grid, a Deslandres table, helps them figure out what jump each line came from.

Sorting Light Lines Into a Grid

When a molecule absorbs or gives off light, it jumps between two main energy levels, and at the same time it can change how strongly it is vibrating. Each combination makes a slightly different spectral line, so you see lots of close-together lines. A Deslandres table sorts these line frequencies into rows and columns. Each column goes with one vibration level of the lower state, and each row with one vibration level of the upper state. If the table is filled correctly, the jump in frequency from one row to the next is the same in every column, and the same goes for columns, which tells scientists they have matched each line to the right vibrations.

Vibronic Transition Assignment Table

In electronic spectroscopy, a molecule jumps from a lower electronic state to an excited one, and at the same time its vibrational level can change, so one electronic transition produces many closely spaced lines called vibronic transitions. A Deslandres table is a way to assign those lines. You arrange the measured line frequencies in a grid so that the difference between neighboring columns, and between neighboring rows, is constant within experimental error. When the table is correct, columns correspond to vibrational levels of the lower electronic state and rows to those of the upper state. The spacing between two rows is the same in every column because it equals the energy gap between two vibrational levels of the same electronic state. The line intensities are set separately by the Franck-Condon principle.

A Deslandres table is a tool in molecular electronic spectroscopy for assigning vibronic transitions, the lines produced when an electronic transition from a lower-lying state to an excited state is accompanied by changes in vibrational level. The observed line frequencies are arranged in a two-dimensional array so that the differences between adjacent columns and between adjacent rows are constant within experimental error. In a correctly constructed table, the columns index the vibrational quantum number of the lower electronic state (v'') and the rows that of the upper state (v'). The constancy follows directly from the level structure: the difference between two successive rows is the energy separation of two given vibrational levels of the upper state, which is independent of the lower-state level involved, and likewise for columns. Line intensities, by contrast, are governed by the Franck-Condon principle and do not affect the arrangement. Filling the table therefore converts a dense list of frequencies into an assignment of each line to a (v', v'') pair.

Structural Signature¶

Sig role-phrases:

Defining carrier — The intensity of the lines is governed by the Franck–Condon principle.
Constitutive relation — Thus, by completing a Deslandres table it is easy to assign the correct vibrational quantum numbers v and v ' for the transition, allowing important molecular properties to be calculated, such as the dissociation energy.
Operating condition — In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions.
Recognition evidence — In such a table, the frequencies of the lines seen in an electronic spectrum of a molecule are collected so that the differences in energy between adjacent columns or rows are all the same (within experimental error).
Admissible variation — When a Deslandres table is filled correctly, the columns represent the vibrational energy levels of the lower electronic state (v ), while the rows represent those for the upper electronic state (v ' ).
Characteristic consequence — Clearly, the difference in energy between two successive rows (columns) must remain constant for any column (row) in the table because this represents the energy difference of two given vibrational levels within the same electronic state.
Failure boundary — Every line seen in the spectrum corresponds to a transition from the lower-lying electronic energy state to an excited electronic state (molecular electronic transition): associated with this, there are corresponding transitions between the vibrational levels of the two states, that give rise to many closely spaced lines.

What It Is Not¶

Not the whole field of cross-domain formal modeling. The node requires the specific identity stated by In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions.
Not an over-broad reading. In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions.
Not an over-broad reading. In such a table, the frequencies of the lines seen in an electronic spectrum of a molecule are collected so that the differences in energy between adjacent columns or rows are all the same (within experimental error).
Not an over-broad reading. The intensity of the lines is governed by the Franck–Condon principle.
Not automatically Tanabe–Sugano diagram. Retrieval proximity does not establish equivalence; the two identities must be compared by carrier, operation, and failure boundary.

Scope of Application¶

Deslandres table applies literally inside cross-domain formal modeling wherever the source-defined carrier and relation can be established. Its documented habitats include:

Documented setting. In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions.
Documented setting. In such a table, the frequencies of the lines seen in an electronic spectrum of a molecule are collected so that the differences in energy between adjacent columns or rows are all the same (within experimental error).
Documented setting. The intensity of the lines is governed by the Franck–Condon principle.
Documented setting. When a Deslandres table is filled correctly, the columns represent the vibrational energy levels of the lower electronic state (v ), while the rows represent those for the upper electronic state (v ' ).
Documented setting. Clearly, the difference in energy between two successive rows (columns) must remain constant for any column (row) in the table because this represents the energy difference of two given vibrational levels within the same electronic state.
Documented setting. Thus, by completing a Deslandres table it is easy to assign the correct vibrational quantum numbers v and v ' for the transition, allowing important molecular properties to be calculated, such as the dissociation energy.

Outside cross-domain formal modeling, the name should be retained only when these same operational conditions survive; otherwise the comparison belongs to the broader parent Pattern or should be marked as analogy.

Clarity¶

A clear use of Deslandres table names the carrier, the operative relation, and the conditions under which the source treats the identity as present. The minimal definition is In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions. The strongest recognition evidence in the frozen account is: In such a table, the frequencies of the lines seen in an electronic spectrum of a molecule are collected so that the differences in energy between adjacent columns or rows are all the same (within experimental error). A report should distinguish that evidence from a proxy, consequence, or common implementation. It should also state the qualification In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions. so that a reader can reproduce the classification rather than infer it from topical resemblance.

Manages Complexity¶

Deslandres table compresses multiple cross-domain formal modeling details into a stable diagnostic relation. The source shows both the central mechanism—thus, by completing a Deslandres table it is easy to assign the correct vibrational quantum numbers v and v ' for the transition, allowing important molecular properties to be calculated, such as the dissociation energy.—and the practical consequence—clearly, the difference in energy between two successive rows (columns) must remain constant for any column (row) in the table because this represents the energy difference of two given vibrational levels within the same electronic state. This compression makes cases comparable while leaving parameters, conventions, exceptions, and evidential quality explicit. It is lossy by design: local history and implementation details may be omitted only when they do not alter the defining relation.

Abstract Reasoning¶

Type the carrier. Identify the cross-domain formal modeling entities to which the claim applies.
State the relation. Use the source-grounded identity: In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions.
Check operation and conditions. In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions.
Demand recognition evidence. In such a table, the frequencies of the lines seen in an electronic spectrum of a molecule are collected so that the differences in energy between adjacent columns or rows are all the same (within experimental error).
Test variation. Change an implementation or setting while preserving when a Deslandres table is filled correctly, the columns represent the vibrational energy levels of the lower electronic state (v ), while the rows represent those for the upper electronic state (v ' ).
Run the collapse test. Remove the defining operation; if the label still seems equally apt, only a topic or correlate was retained.
Reduce cautiously. When the specialist conditions cannot be carried, route the residual comparison to Pattern.

Knowledge Transfer¶

Within the home domain. Knowledge about Deslandres table transfers literally when a new case preserves the same carrier type, relation, and recognition test. In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions. In such a table, the frequencies of the lines seen in an electronic spectrum of a molecule are collected so that the differences in energy between adjacent columns or rows are all the same (within experimental error).

Beyond the home domain. No canonical parent is asserted for Deslandres table. An outside case receives the specialist name only when the same typed roles and rejection conditions can be filled literally; otherwise the comparison remains an analogy pending later graph densification.

Examples¶

Canonical¶

Thus, by completing a Deslandres table it is easy to assign the correct vibrational quantum numbers v and v ' for the transition, allowing important molecular properties to be calculated, such as the dissociation energy. This case is canonical because it supplies a concrete carrier and lets the defining relation be checked rather than merely named.

Mapped back: carrier → the entities in the documented case; operation → In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions; recognition evidence → In such a table, the frequencies of the lines seen in an electronic spectrum of a molecule are collected so that the differences in energy between adjacent columns or rows are all the same (within experimental error)

Applied / In Practice¶

In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions. The applied case shows how the identity is used under a second setting or qualification while keeping the same operative relation.

Mapped back: changed setting → the applied context; invariant → In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions; boundary → the case exits the class when in electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions

Structural Tensions¶

T1 — Stable identity versus admissible variation. In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions. The tension matters because emphasizing only one side either dissolves the identity or overstates what the evidence and domain conventions warrant.

Diagnostic: Which changes preserve the defining relation, and which replace it?

T2 — Recognition versus proxy. In such a table, the frequencies of the lines seen in an electronic spectrum of a molecule are collected so that the differences in energy between adjacent columns or rows are all the same (within experimental error). The tension matters because emphasizing only one side either dissolves the identity or overstates what the evidence and domain conventions warrant.

Diagnostic: Does the cited evidence establish the identity or only a correlated sign?

T3 — Definition versus implementation. The intensity of the lines is governed by the Franck–Condon principle. The tension matters because emphasizing only one side either dissolves the identity or overstates what the evidence and domain conventions warrant.

Diagnostic: Is the observed implementation constitutive, optional, or merely common?

T4 — Scope versus overextension. When a Deslandres table is filled correctly, the columns represent the vibrational energy levels of the lower electronic state (v ), while the rows represent those for the upper electronic state (v ' ). The tension matters because emphasizing only one side either dissolves the identity or overstates what the evidence and domain conventions warrant.

Diagnostic: Can every claimed application fill the same typed roles without metaphor?

T5 — Transfer versus domain accent. The intensity of the lines is governed by the Franck–Condon principle. The tension matters because emphasizing only one side either dissolves the identity or overstates what the evidence and domain conventions warrant.

Diagnostic: Does the receiving case instantiate Deslandres table literally, co-instantiate Pattern, or only resemble it?

T6 — Autonomy versus reduction. Thus, by completing a Deslandres table it is easy to assign the correct vibrational quantum numbers v and v ' for the transition, allowing important molecular properties to be calculated, such as the dissociation energy. The tension matters because emphasizing only one side either dissolves the identity or overstates what the evidence and domain conventions warrant.

Diagnostic: What does Deslandres table distinguish that the broader parent Pattern leaves together?

Structural–Framed Character¶

Deslandres table is mixed or framed-leaning. Its structural side is the repeatable organization summarized by In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions. Its framed side is the cross-domain formal modeling vocabulary that fixes the carrier, evidence, exceptions, and admissible transformations.

Evaluative weight: the identity can be stated descriptively even when applications carry practical stakes. Human-practice dependence: the source-grounded carrier determines whether the relation exists independently or is constituted by a practice. Institutional origin: disciplinary conventions stabilize the name and test. Vocabulary portability: In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions. Import versus recognition: literal transfer requires the same mechanism; shape alone is analogy.

Its portable skeleton is Pattern. Its character: a recurring specialist identity whose thin organization can be abstracted, while its operational meaning remains domain-bound.

Structural Core vs. Domain Accent¶

What is skeletal. In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions. The stable skeleton is the typed relation expressed in that definition and the entry's recognition and collapse tests. The source identifies these operative conditions: The intensity of the lines is governed by the Franck–Condon principle. Thus, by completing a Deslandres table it is easy to assign the correct vibrational quantum numbers v and v ' for the transition, allowing important molecular properties to be calculated, such as the dissociation energy. It further constrains recognition and variation through: In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions. In such a table, the frequencies of the lines seen in an electronic spectrum of a molecule are collected so that the differences in energy between adjacent columns or rows are all the same (within experimental error).

What is domain-bound. cross-domain formal modeling supplies the operative entities, technical vocabulary, warrants, and exceptions that make Deslandres table literal. Its documented scope includes the condition that In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions. Another bounded application condition is that In such a table, the frequencies of the lines seen in an electronic spectrum of a molecule are collected so that the differences in energy between adjacent columns or rows are all the same (within experimental error). These are not decorative examples; they determine which carrier and evidence can fill the abstraction's roles.

Why no parent is asserted. Removing those specialist details does not currently yield one live catalog node that is a necessary genus for every instance. The entry is therefore approved as unparented rather than attached by topical resemblance. Its collapse evidence remains specific—When a Deslandres table is filled correctly, the columns represent the vibrational energy levels of the lower electronic state (v ), while the rows represent those for the upper electronic state (v ' ).—and future graph densification may discover a defensible relation only if it preserves that boundary.

Approved unparented node. No current live node supplies a defensible necessary genus or structural prerequisite for Deslandres table. The reviewed identity is: In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions. The accelerated suggestion was declined because topical or lexical similarity does not establish hierarchy; the node is admitted without a parent pending later graph densification.
Related reasoning operations. Evidence, representation, comparison, classification, transformation, or evaluation may participate in particular cases, but participation does not make any one of them a necessary parent of every instance.

Neighborhood in Abstraction Space¶

Deslandres table sits in a sparse region of the domain-specific corpus (75^th percentile for distinctiveness): few abstractions share its structure, so a faithful description tends to retrieve it precisely.

Family — Unclustered & Miscellaneous (2551 abstractions)

Nearest neighbors

Computed from structural-signature embeddings · 2026-10-08

Not to Be Confused With¶

Pattern. The parent omits the specialist differentia. Tell: Can the case establish In electronic spectroscopy, constructing a Deslandres table is a useful method to assign vibronic transitions?
Tanabe–Sugano diagram. A normalized energy-level diagram showing how electronic states of a transition-metal ion vary with ligand-field strength relative to interelectronic repulsion. Tell: Which entry's carrier, operation, and failure condition are satisfied?
Chemical space. The conceptual set of chemically admissible molecules under declared construction rules, represented by coordinates or descriptors that permit comparison, search and coverage analysis. Tell: Which entry's carrier, operation, and failure condition are satisfied?
Cophonicity. A vibrational-overlap metric measuring how strongly two atomic species contribute together within a selected frequency range. Tell: Which entry's carrier, operation, and failure condition are satisfied?
A measurement, proxy, or consequence. Those may provide evidence without being the identity. Tell: Would Deslandres table remain present if the detector or downstream effect changed?
A metaphorical analogue. A similar shape outside cross-domain formal modeling lacks the specialist mechanism. Tell: Do the native roles transfer literally, or only the parent Pattern?

References¶

Frozen Wikipedia discovery revision: https://en.wikipedia.org/wiki/Deslandres_table (revision 1087300595).
Preserved source candidate: https://archive.org/details/modernspectrosco0000holl_t7j3

The frozen Wikipedia revision is discovery provenance. The retained source set was reviewed for identity, formal or operational relation, and scope. The encyclopedia's structural synthesis is bounded to those claims; a thin authority surface is recorded as a nonblocking source-strengthening repair rather than concealed.