Skip to main content

Questions tagged [gaussian]

For questions related to the Gaussian electronic structure program

23 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
9 votes
0 answers
115 views

How does the line search in geometry optimisations work?

I am trying to write a Newton-Raphson geometry optimisation script in python (Current version of my code) using the energy, gradient and Hessian from Gaussian 16. In order to reach a minimum, I would ...
evd's user avatar
  • 91
4 votes
1 answer
44 views

How to use rigid scan with dummy atoms in gaussian?

I am trying to use rigid scan using gaussian 09. In my case, there are three water molecules and I have placed a dummy atom at the centroid of the three water molecules. For simplicity, I want to ...
Pro's user avatar
  • 1,024
4 votes
0 answers
49 views

May I change the ICntrl variable in Gaussian 16?

Ive been trying to do energy calculations under the influence of a perturbative field with the BLYP and B3LYP functionals. Using the following input files: BLYP: ...
Atom's user avatar
  • 1,005
4 votes
0 answers
21 views

bandstructure calculation of two-dimensional ferrovalley (RuClBr) in quantum espresso

We try to calculate bandstructure of single layer RuClBr reported in fig.4 of 'https://pubs.rsc.org/en/content/articlelanding/2016/pq/d3nr00346a/unauth'. But our obtained bandstructure is not similar ...
manouchehr's user avatar
4 votes
0 answers
91 views

Can I run Gaussian on Google Collab

Can I use Google Collab to run my Gaussian calculations? Due to the lower specification of my system, I can not run my calculations. I have to generate .wfn file. Is there any other idea or ...
Inorganic Chemistry's user avatar
4 votes
0 answers
53 views

Struggling with Mixed Basis Set Inclusion for IRC Calculations

I'm trying to compute the IRC for a W complex, and I'm using Def2TZVP for W and 6-311G** for the rest of the atoms. However, when I include the mixed basis set, Gaussian 16 generates a syntax error. I ...
user8769's user avatar
4 votes
0 answers
56 views

How to compute only part of molecular Hessian accurately (hybrid Hessian or partial Hessian calculation)?

Hessian is required for minimisation and transition state (TS) optimisation algorithms. While the full Hessian at a certain level of theory is calculated usually for TS optimisation, usually ...
S R Maiti's user avatar
  • 7,011
4 votes
0 answers
60 views

How to calculate charge transfer (CT) in NBO Analysis using Gaussian 09?

I have a coronene structure, functionalized with hydroxyl groups. I want to calculate the charge transfer (CT) between the coronene and the hydroxyl group, using NBO analysis as implemented in ...
Bruno's user avatar
  • 233
3 votes
0 answers
39 views

How to compute molar Gibbs free energy (chemical potential) for single molecule using gaussian09?

I want to calculate the Gibbs free energy of single gas molecule (AsH3) using Gaussian 09, but I am confused between "Thermal correction to Gibbs Free Energy" and "Sum of electronic and ...
Abhishek's user avatar
3 votes
0 answers
30 views

Constrained geometry optmization: Molecule interacts with its surroundings

I have a water cluster(suppose) generated from MD run. Now, I want to optimize the geometry of only one water molecule of interest using QC methods (e.g. B3LYP/6-31+G(d,p)). I intend that the water ...
Pro's user avatar
  • 1,024
3 votes
0 answers
175 views

Advise in generating ESP surfaces from Gaussian .cube files using the IQmol software

I am trying to generate an ESP surface of a Gaussian09 calculation using the iqmol software. I have used Gaussview to visualize the ESP surface by generating .cube files from .fchk files (using the ...
Kevin Freddo's user avatar
3 votes
0 answers
66 views

How to choose the orientation of basis functions in a Gaussian calculation?

I am trying to run a g09 calculation for a D5h symmetric molecule using the HF/LANL2DZ level of theory. The molecule is pentagonal planar in geometry, and I would like to visualize the canonical ...
Kevin Freddo's user avatar
2 votes
0 answers
40 views

Calculation of dipole moment from gaussian

I am trying to calculate the dipole moment of water molecule using Gaussian16. The problem I face is the use of Density=Current keyword in the route section. Here is the input file and output file ...
Pro's user avatar
  • 1,024
2 votes
0 answers
23 views

Why am I getting wrong information about basis functions on running gaussian calculation using the 6-31G basis set for the krypton atom?

This is the information about basis functions which I am getting on doing Gaussian calculation. But according to the best of my knowledge Kr has six primitive Gaussians for 1s, 2s,2p, 3s, and 3p ...
user avatar
2 votes
0 answers
23 views

Are there any good tutorials on SHARC-Gaussian interface?

I am an aspiring quantum chemist planning on trying out the SHARC approach to study excited state proton transfer dynamics of organic molecules. I am comfortable with Gaussian 16 as that is the ...
Uranium238's user avatar
2 votes
0 answers
23 views

How to seperate structures in bulk with connectivity from a relaxed scan in Gaussian 16?

I aim is to construct the PES for a molecule considering a specific bond length as the scan coordinate. I am using the Relaxed-Scan feature of Gaussian 16 for this using the ...
Uranium238's user avatar
2 votes
0 answers
76 views

Frequency calculation using Quantum Espresso

I want to calculate the frequency using quantum espresso. How can I get the input file of frequency calculation using QE? ...
Boka Fikadu Banti's user avatar
2 votes
0 answers
17 views

Can I define molecular units on NBO3.1 or NBO6.0?

I'm studying donor-acceptor charge transfer (CT) process between tetrakis(m2-acetato)-di-Wolframium (acceptor) with an acetonitrile (donor) at the B3LYP-D3BJ/def2-TZVPD level of theory. The W···N ...
Juandiego Velasquez Benites's user avatar
2 votes
0 answers
45 views

How much should you shift fragment energies to create an energy level diagram?

I am creating an energy level diagram for the orbitals of [XeF₅] - molecule produced by two fragments: [Xe] 4+ and [F₅] 5-. There is a very large energy difference between the two fragments, so I ...
Kevin Freddo's user avatar
2 votes
0 answers
73 views

Help setting the input geometry into standard orientation for a single point g09 calculation

I am trying to run a single point g09 calculation for a pentagonal planar molecule with D5h symmetry using the B3LYP/LANL2DZ level or theory. I would like the calculation to use symmetry, however the ...
Kevin Freddo's user avatar
2 votes
0 answers
30 views

What is the procedure to calculate the vibrationally resolved UV-Vis spectrum in solvent with Gaussian?

I followed the tutorial reported here to calculate the vibrational resolved spectrum in vacuum. The spectrum seems ok and it is actually close to the experimental one. However, I would like to add the ...
Laura's user avatar
  • 1,267
1 vote
0 answers
21 views

Optimization error in quantum dot graphene doping with antimony atoms

...
fatemeh's user avatar
  • 11
1 vote
0 answers
73 views

Fluorescence solvated band shape in Gaussian16

I am trying to calculate the fluorescence spectra in solvent with Gaussian16. I followed the example reported here to calculate the value of the vertical emission. However, in the same link, I read: ...
Laura's user avatar
  • 1,267