Questions tagged [excited-states]

Refers to an atom or molecule with an electronic configuration in a higher than normal energy state than it's ground-state. The excited-state may relax radiatively or non-radiatively.

Filter by
Sorted by
Tagged with
4 votes
0 answers
61 views
+100

Do the orbital energies of ground-state Dyson orbitals exactly capture arbitrary excitation energies and/or ionisation potentials/electron affinities?

According to an answer to my question on whether the Kohn-Sham orbital energies theoretically exactly capture arbitrary ionisation potentials and/or excitation energies, the answer is no for both ...
6 votes
2 answers
191 views

Closed-form expression for excitation energies, given the exact XC functional

In an answer to my question regarding the theoretical rigour in computing excitation energies using only the Kohn-Sham orbital energies, the rigour turned out to be nonexistent. After looking this ...
5 votes
1 answer
100 views

Question on generalised Kohn-Sham "band gap"

It is often said that the optical band gap, i.e. the first excitation energy, of a species is exactly equal to the difference between the (Kohn-Sham) HOMO and LUMO. This would mean that the state of ...
3 votes
0 answers
35 views

Excited States of Lithium in MOLPRO

I am trying to run a exciattion energy calculation for a Lithium atom. Is there a way to force the initial HF calculation to follow a specific excited state configuration, i.e. to skip or leave some ...
5 votes
2 answers
262 views

Vertical transition, 0-0 transition, and experimental spectra

I am currently working on a machine learning with spectroscopy. I had learnt about the Franck-Condon principle and the vibronic coupling in photochemistry courses in my undergraduate lectures. However,...
  • 5,834
9 votes
2 answers
75 views

Any software that could do surface hopping?

I am trying to understand how to do the time-dependent simulation of the electron transfer, I find that the popular method is surface hopping, but I am not sure if there is any software that could ...
  • 1,843
4 votes
0 answers
149 views

STEOM-DLPNO-CCSD

I have to calculate the S1 - T1 energy gap using coupled cluster (STEOM-DLPNO-CCSD) in ORCA. The output file contains only singlet energies. IROOT=... (no notation singlet or triplet). I tried adding &...
11 votes
0 answers
102 views

Calculating Core-Level Binding Energies (XPS) using DFT

I'm pretty new to DFT calculations but I'm trying to learn how XPS calculations are set up, particularly for open-shell molecular systems in common non-periodic DFT codes. A highly related secondary ...
6 votes
0 answers
48 views

Transition dipole moment derivative TURBOMOLE

I am trying to calculate transition dipole moment derivatives using Turbomole 7.3. For some reason, and although I think I included the neccessary keywords to perform such a calculation, they are not ...
9 votes
2 answers
335 views

Is it reasonable to calculate TDDFT excitation energies at a geometry optimized with a different method?

I am working on a project where I have to calculate the TDDFT excitation energies of organic molecules (to compare to the experimental UV/visible i.e. optical absorption spectrum). Now, if I ...
  • 5,834
9 votes
2 answers
362 views

Calculating the excited state dipole moment

I am trying to calculate the dipole moment of an excited state, using "Gaussian" software. My input commands were: ...
  • 163
7 votes
1 answer
833 views

How can I calculate the energy gap between the singlet and triplet state using ORCA?

I came across this publication that calculates the $S_1$ - $T_1$ energy gap using TDDFT as implemented in Gaussian. I would like to do the same using ORCA. Im extremely new to ORCA and local orbital ...
6 votes
1 answer
75 views

Accurate electron-hole localization for charge-transfer transitions

I'm studying the nature of electronic excitation in conjugated organic dyes. To define the donor and acceptor part I've run TDDFT and CIS calculation, they both gave similar set of configurations for ...
  • 2,323
8 votes
1 answer
110 views

Excited states using ORMAS flag in GAMESS

I am trying to calculate the excited states using single reference CISD on $\ce{CH3OH},$ using ORMAS' CI-X option in GAMESS. As a test example I am using the $\ce{CH3OH}$ that has 2 core, 7 occ. ...
15 votes
3 answers
1k views

Can you estimate the electronic excited state lifetime of a molecule?

I want to estimate the lifetime of an electronic excited state. Lets assume there is only radiative coupling via spontaneous emission from this state to the ground state. I can optimize the excited ...
6 votes
2 answers
203 views

Excited state normal mode frequency doesn't match for NH3

I am trying to optimize the geometry of excited state NH3 and get the corresponding normal modes for excited states. I am trying to get the frequencies as mentioned in this reference. They claim to ...
8 votes
1 answer
183 views

Optimization and vibrational analysis of excited state CO using GAMESS

I am facing some problems in performing HESSIAN analysis on excited states of molecules: I am testing it out with CO. My input file to GAMESS is pasted below. Could ...
16 votes
2 answers
849 views

How to understand the spin of exciton?

In very recent years, exciton physics has been intensively explored as the emergence of 2D materials. Exciton is a bound electron-hole pair and is bosonic, namely hosting an integer spin. My first ...
  • 14k
13 votes
0 answers
126 views

What are the recent developments of GW@BSE to simulate the excited properties of materials?

A twin question related to the TDDFT method is asked in another post. But any comparisons between both methods in recent developments are welcome. The time-dependent density functional theory (TDDFT) ...
  • 14k
19 votes
0 answers
149 views

What are the recent developments of TDDFT to simulate the excited properties of materials?

The time-dependent density functional theory (TDDFT) and the many-body perturbation method (GW@BSE) are considered as the two most popular and successful methods to describe the excited-stated ...
  • 14k
13 votes
1 answer
110 views

Photoemission Spectra of Solids

I know that in non-periodic codes such as Gaussian the fluorescence spectra of molecule can be calculated in the following manner. Relax geometry TD-DFT to find excited state Relax excited state ...
13 votes
1 answer
124 views

What progress has been made in modelling photocatalytic reactions on semiconductor surfaces?

For example, are there any methods to allow for modeling of photo-oxidation or photo-reduction of a compound on a semiconductor surface? It appears there has been a lot of work on the bulk properties ...
21 votes
2 answers
374 views

What methods are available for excited state calculations in solids?

In the spirit of a succint answer (3 paragraphs maximum) to create a useful resource, what are the types of excited state calculation available for solids? Please add to the list: Quasiparticle ...
  • 10.4k
10 votes
2 answers
195 views

Is there an example where TD-DFT fails to provide sufficient accuracy for a small system, where RI-CC2 is sufficient?

Time-dependent density functional theory (TD-DFT) is considered to be more efficient (in terms of its accuracy/speed ratio) than alternatives such as the approximate coupled-cluster singles and ...
16 votes
1 answer
164 views

What methods can be used to calculate excited-states in molecular crystals?

In periodic systems plane-wave basis functions are often used. In a previous question on this site it was questioned if plane-wave basis-sets are reliable for modeling adsorption-processes The ...
  • 7,794