Questions tagged [basis-set]

A set of (basis) functions make up a basis set. These functions (generally) represent atomic orbitals whose linear combinations are used to make molecular orbitals (LCAO-MO) in computational chemistry.

12 questions with no upvoted or accepted answers
Filter by
Sorted by
Tagged with
4
votes
0answers
103 views

Variational method: Hydrogen atom ground state in STO-3G basis expansion

I computed numerically the ground state energy of hydrogen by variational procedure, firstly expanding the wave function over the s-wave basis set STO-3G $$\psi(r)=\sum_{i=0}^3 C_{i} e^{-\alpha_ir^2}$$...
4
votes
0answers
361 views

What is the ANO-RCC basis set and how does it work?

On the basis set exchange, the ANO-RCC basis looks huge, even for hydrogen: ...
3
votes
0answers
99 views

What are the cheapest basis sets able to model intermolecular dipole interactions inside a metal complex and give good relative energies, with DFT?

As a example, If I have a square planar complex of a cation with both a weakly polar ligand (X) and strongly polar ones, like ammonia and water I expect a bit of stabilization due to formation of a ...
3
votes
0answers
84 views

How to find a full electron basis set that approximate a given ECP basis set?

In computational chemistry of transition metals, there are many popular basis sets, from pople+LANL2DZ mixed basis sets, to Ahlrich and Karlsruhe basis sets like def-SVPD, def2-TZVPPD. Often the ECP ...
3
votes
0answers
83 views

Reducible representations - choice of new basis

I was looking at this tutorial about reductions of representations. At first, the basis consists of four orbitals $(s_N, s_1, s_2, s_3)$ and the representations look like this and we want to reduce ...
3
votes
0answers
322 views

Which Basis Set is suitable For Mercury-complex in DFT calculations?

Which Basis Set is suitable For Mercury-complex in DFT calculations? Please provide the answers with any journal reference.
2
votes
0answers
159 views

Total SCF Energy with Pseudopotentials

Is there a physical meaning to the SCF energy of a molecule obtained using pseudopotentials to represent the core electrons of heavy atoms (for example gold)? I've been running calculations in ...
1
vote
0answers
79 views

How do you optimize an organo-metalic compound containing cerium in in Gaussian?

I am trying to perform optimisation of the molecule attached. I need to get partial charges and frequencies. The issue is that it doesn't converge with following input: ...
1
vote
0answers
192 views

Hartree Fock for an atom (Beryllium)?

I'm working on solution of Hartree-Fock equation for Beryllium in configuration $1s^2 2s^2$, expanding the orbital with STO-3G basis $$\phi_k=\sum_{p=0}^3 C_{kp}e^{-\alpha_{kp}r^2}$$ I know the values ...
0
votes
0answers
114 views

Is this approximate equivalence table between Pople's basis sets and Jensen's DFT attuned polarization consistent basis sets (pcseg-n) correct?

I have some calculations results I runned previously using Pople's basis sets, mostly 6-311+G(d), under Gaussian09. These days I read some texts on Frank Jensen's family of polarization consistent, ...
0
votes
0answers
51 views

Forming Basis Functions from 6-31G Basis Set for Carbon Atom

I am a computer science grad and I am working to write an electronic structure calculation program and I am stuck at forming basis functions using 6-31G Basis set for atoms having higher atomic ...
0
votes
0answers
132 views

What is meaning of LAV2P basis set?

I am working on energy optimization of molecular structure using DFT with Schrödinger software and I found that job is running on LAV2P basis set. I want to know what is the meaning of this basis set ...