User Wychh

20 votes

2 answers

2k views

What is a Padé approximant?

asked Aug 12, 2021 at 12:21

12 votes

2 answers

1k views

What do the rows and columns of a Fock matrix represent?

asked Jul 9, 2020 at 15:10

12 votes

2 answers

950 views

For DFT and Hartree-Fock, how can we know that we have a true minimum? Is there an equivalent to the "frequency analysis" for geometry optimization?

asked Jul 28, 2021 at 17:41

11 votes

1 answer

2k views

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

asked Jul 16, 2020 at 21:24

10 votes

1 answer

2k views

Convert reduced density matrix from M.O. to A.O. basis

asked Jul 19, 2021 at 9:05

9 votes

1 answer

163 views

The correlation energy from frozen natural orbtials (FNOs) using CCSD and MPBT(2)?

asked Jun 3, 2020 at 9:26

9 votes

3 answers

2k views

What are the advantages of the Davidson diagonalization method over other sparse matrix diagonalization methods?

asked Aug 13, 2021 at 15:28

9 votes

1 answer

421 views

PySCF: eigenvalues, non-integer occupation, CISD calculations, and frozen lists

asked Aug 20, 2020 at 12:31

9 votes

2 answers

488 views

Normalization constant and Roothaan Equations

asked Aug 31, 2020 at 12:32

8 votes

1 answer

427 views

Semi-canonicalisation vs canonicalisation of the Fock matrix and orbitals

asked Aug 18, 2020 at 14:50

7 votes

1 answer

623 views

PySCF: Implementing SHCI frozen argument

asked Sep 30, 2020 at 11:45

7 votes

1 answer

914 views

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

asked Sep 2, 2020 at 12:55

7 votes

1 answer

1k views

What information does the 1RDM contain?

asked Jul 7, 2022 at 23:14

6 votes

0 answers

65 views

Orbital space clustering [closed]

asked Aug 12, 2021 at 8:18

6 votes

1 answer

60 views

Multi-configurational self-consistent field coefficients

asked Aug 13, 2021 at 13:36

5 votes

1 answer

209 views

Translate between ibrav and space_group Quantum Espresso inputs

asked Feb 16 at 13:44

5 votes

1 answer

892 views

How to build a unit cell in ASE?

asked May 8, 2023 at 17:15

5 votes

1 answer

506 views

PySCF: atomic basis Fock matrix changes after mo_coeff update

asked Sep 11, 2020 at 10:28

5 votes

1 answer

365 views

PySCF: 2-index and 3-index matrix

asked Oct 2, 2020 at 17:41

4 votes

2 answers

491 views

Ionic relaxation with ASE (Atomic Simulation Environment)

asked May 10, 2023 at 21:39

4 votes

1 answer

334 views

Is there a difference between `space_group` and `ibrav` in terms of Quantum espresso performance?

asked Feb 22 at 0:35

3 votes

0 answers

133 views

How to use space_group for Quantum Espresso

asked Feb 17 at 0:04

2 votes

0 answers

148 views

Phonon Calculation (IR Spectrum) in Quantum Espresso

asked Jul 8, 2023 at 3:54

1 vote

1 answer

208 views

Use Atomic Simulation Environment to set DFT+U parameters with Quantum Espresso

asked May 18, 2023 at 18:39

Stack Exchange Network

24 Questions

What is a Padé approximant?

What do the rows and columns of a Fock matrix represent?

For DFT and Hartree-Fock, how can we know that we have a true minimum? Is there an equivalent to the "frequency analysis" for geometry optimization?

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

Convert reduced density matrix from M.O. to A.O. basis

The correlation energy from frozen natural orbtials (FNOs) using CCSD and MPBT(2)?

What are the advantages of the Davidson diagonalization method over other sparse matrix diagonalization methods?

PySCF: eigenvalues, non-integer occupation, CISD calculations, and frozen lists

Normalization constant and Roothaan Equations

Semi-canonicalisation vs canonicalisation of the Fock matrix and orbitals

PySCF: Implementing SHCI frozen argument

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

What information does the 1RDM contain?

Orbital space clustering [closed]

Multi-configurational self-consistent field coefficients

Translate between ibrav and space_group Quantum Espresso inputs

How to build a unit cell in ASE?

PySCF: atomic basis Fock matrix changes after mo_coeff update

PySCF: 2-index and 3-index matrix

Ionic relaxation with ASE (Atomic Simulation Environment)

Is there a difference between `space_group` and `ibrav` in terms of Quantum espresso performance?

How to use space_group for Quantum Espresso

Phonon Calculation (IR Spectrum) in Quantum Espresso

Use Atomic Simulation Environment to set DFT+U parameters with Quantum Espresso