How do separate spin part and space part for a slater determinant ?

I am trying to write down the slater determinant for 10 electron filling from 1s up , 1s down, 2s up, 2s down, 2px up, 2px down, 2py up,2py down, 2pz up, 2pz down, There are totally 10 single...

06 July 2019 819 1 View

In Quantum Monte carlo method, what is the justification that product of up and down spin slater determinant equal to total slater determinant ?

I am reading the book on MONTE CARLO METHODS IN AB INITIO QUANTUM CHEMISTRY by Hammond and Lester. (Chapter 5-Variational Trial Functions, Section 5.3-Hartree Fock and Beyond, Sub-Section 5.3.3...

03 April 2019 4,735 3 View

How do I solve this combinatorics problem with conditions?

I have N lattice points which are arranged linearly and equally spaced. I want to make connections(say with some wire or thread) with each lattice site with another. The first one has N-1...

03 April 2019 7,521 19 View

How to run orca for some 100 files using batch program in windows and linux ?

I have large number of input files to run in orca software. I have named the files as follows, orcafile0, orcafile1,...and so on upto 512 files. How do I write a batch program to run all the files...

02 March 2019 7,697 1 View

How to run ORCA software with multiple input blocks in one input file and getting multiple outputs corresponding to the input blocks ?

Is it really possible to give multiple input blocks in a single file ? Can ORCA recognize it as separate input and run them separately and produce the output for multiple inputs

02 March 2019 3,508 6 View

What is the Best Gaussian basis sets to represent slater type orbitals( particularly for hydrogen ) ?

What is the best Gaussian basis set which (almost ) exactly fits well with slater type orbitals. I want to know at least for hydrogen molecule. I mean , I want to represent 1s,2s and all the 2p...

02 March 2019 4,188 1 View

How to install PSi4 Quantum Chemistry Software Package in Python in Windows 8 ?

I wanted to install PSi4 a quantum chemistry software package in windows 8. However, the Psi4 website says about Linux and Mac but not about windows. Is it really possible to install Psi4 in...

01 February 2019 4,354 1 View

How to install pyquante package in python ?

I am trying to solve two electron integrals and one electron integrals numerically, using python. How far pyquante is useful to solve these integrals numerically and how to install it and can...

09 October 2018 3,420 1 View

How to solve two electron integrals numerically ?

I am trying to solve numerically Helium atom problem (spectrum of two electrons with interaction with nucleus and electronic repulsion).. I have excluded the kinetic term of nucleus and put the...

09 October 2018 2,921 0 View

Why in mathematica numerical integration of two electron integrals is not converging ?

I was trying to construct matrix elements for helium atom to get the electronic energy spectrum. I used 1s, 2s, and the three 2p orbitals to construct the two body basis. I treated the electron...

09 October 2018 980 0 View

error in running a model in Abaqus

Excessive rotation of nodes in node set ErrNodeExcessRotation-Step1

17 August 2021 0 0 View

error in modelling model in Abaqus

Excessive rotation of nodes in node set ErrNodeExcessRotation-Step1

17 August 2021 0 0 View

MD MOE RMSD

How to calculate the RMSD values for a MD simulation using MOE?

07 August 2021 0 0 View

MD MOE RMSD

How to calculate the RMSD values for a MD simulation using MOE?

07 August 2021 0 0 View

MGL tools

20 June 2021 0 0 View

fatal error

When I tried to energy minimization my system, I got fatal error as below. Fatal error: Atomtype opls_116 not found Although I've already added this line: ; include water #include "oplsaa.ff/spc.itp" to [molecultype] directive in my topology.

16 June 2021 0 0 View

fatal error

When I tried to energy minimization my system, I got fatal error as below. Fatal error: Atomtype opls_116 not found Although I've already added this line: ; include water #include "oplsaa.ff/spc.itp" to [molecultype] directive in my topology.

16 June 2021 0 0 View

fatal error

When I tried to energy minimization my system, I got fatal error as below. Fatal error: Atomtype opls_116 not found Although I've already added this line: ; include water #include "oplsaa.ff/spc.itp" to [molecultype] directive in my topology.

16 June 2021 0 0 View

fatal error

When I tried to energy minimization my system, I got fatal error as below. Fatal error: Atomtype opls_116 not found Although I've already added this line: ; include water #include "oplsaa.ff/spc.itp" to [molecultype] directive in my topology.

16 June 2021 0 0 View

flexibility of polymers chain

effect of double bond on the flexibility of polymers

07 April 2021 0 0 View