Questions tagged [pyscf]

For questions about or related to the PySCF electronic structure package for Python

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3 votes
1 answer
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Why is my CISD restart failing in PySCF?

A case that works In my answer to Restarting an FCI calculation in PySCF, I provided a folder full of input and output files that demonstrates saving (as a numpy ...
I have no free time anymore's user avatar
8 votes
1 answer
295 views

How can I build the wheels necessary for a quick installation of PySCFad on a "compute node"?

The following is the procedure I have been following: Install PySCFad ...
I have no free time anymore's user avatar
11 votes
1 answer
1k views

How to calculate the Fock matrix in the molecular orbital basis PySCF?

I am interested in calculating the Fock matrix in the molecular orbital basis with PySCF, though I am not clear on the methodology behind this task. In my attempt, I use the following script (for the ...
Wychh's user avatar
  • 2,157
10 votes
4 answers
2k views

Codes for post-processing Gaussian cube files?

I have generated MOs of a molecular system and I need to recreate its electronic density via $\rho(r)=\sum_{A_i}|\psi_i(\mathbf{r})|^2$ where $A$ is a set of occupied MOs. I am trying to do this via ...
mykd's user avatar
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7 votes
1 answer
264 views

Computing analytic derivatives of molecular Hamiltonians obtained from solving Hartree-Fock equations

I'm currently working on a quantum chemistry project, I am dealing with a second-quantized electronic Hamiltonian (corresponding to some molecule), written in terms of fermionic creation and ...
Jack Ceroni's user avatar
7 votes
1 answer
842 views

Why is my quantum chemistry software not printing as many 2e- integrals as I expect?

Background: In Hartree-Fock theory, the two-electron integral is given by: $[ij|kl]$ = $\int dx_{1}dx_{2}(\chi_{i}(x_{1})\chi_{j}(x_{1})\frac{1}{r_{12}}\chi_{k}^{*}(x_2)\chi_{l}(x_{2})$ I am ...
Wychh's user avatar
  • 2,157
5 votes
1 answer
203 views

Calculating first and second derivatives of a molecular Hamiltonian?

I'm interested in computing first and second derivatives of molecular Hamiltonians with respect to nuclear coordinates. I've been using Psi4 and PySCF to perform Hartree-Fock calculations, and I was ...
Jack Ceroni's user avatar
5 votes
1 answer
54 views

A matrix form used in the Quantum Annealer Eigensolver (QAE)

In the paper "Computing molecular excited states on a D‑Wave quantum annealer", PySCF is employed to compute the TDA matrix. Then a few of the lowest eigenvalues and eigenvectors of a TDA ...
Hadeel Moustafa's user avatar
4 votes
1 answer
301 views

What's the best code for getting 1-particle and 2-particle density matrices with CCSD(T) in Python?

I have been using PySCF to calculate the 1-particle and 2-particle density matrix from ccsd(T) wavefunction using these modules in-built in PySCF make_rdm1() and <...
Pro's user avatar
  • 964
4 votes
1 answer
72 views

Table of Largest CI Components in PySCF CASSCF Calculation

I was running a simple CASSCF calculation in PySCF on the TMM biradical. It was a CASSCF (4,4) state averaged calculation where the energies of the first 3 roots were calculated. The simulation output ...
Abhishek R Nath's user avatar
4 votes
1 answer
603 views

Molecular orbital values on grid points in PySCF?

I am looking for a way to easily evaluate individual molecular orbitals on a grid(assuming a single determinant method for now) in PySCF. I am aware on how to generate efficient grids for real-space ...
Szgoger's user avatar
  • 624
3 votes
1 answer
170 views

Is PySCF able to print checkpoint files during a CISD calculation?

The problem I've described how to restart a CISD calculation in my answer to the question: Restarting an FCI calculation in PySCF, but this requires all iterations of the CISD calculation to finish, ...
I have no free time anymore's user avatar
2 votes
1 answer
302 views

Generate grid coordinates from PySCF DFT package for plotting grid points

As can be read in the pyscf.dft documentation, there should be the possibility of generating the coordinates of the grid for numerical integration. According to the documentation, one can generate the ...
C_Swann22's user avatar
  • 573
1 vote
1 answer
355 views

PySCF: How to do CCSD calculations from an FCIDUMP file in HDF5 format?

Recently my question: Why does CCSD work, but not CCSD(T), after reading an FCIDUMP in PySCF? lead to a bug fix that allows users to do CCSD(T) calculations from an FCIDUMP file in PySCF. That was ...
I have no free time anymore's user avatar