QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: Habib on December 15, 2023, 21:46

Title: Simulation of COHP and pCOHP
Post by: Habib on December 15, 2023, 21:46

Hello,

Is it possible to simulate the Crystal Orbital Hamilton Population (COHP) and projected Crystal Orbital Hamilton Population (pCOHP) of a material using the QuantumATK?

Kind Regards
Habib

Title: Re: Simulation of COHP and pCOHP
Post by: Jahanzaib on December 16, 2023, 18:29

QuantumATK did not have the direct capability to simulate Crystal Orbital Hamilton Population (COHP) or projected Crystal Orbital Hamilton Population (pCOHP) for materials but I think, in future, it might have.

Title: Re: Simulation of COHP and pCOHP
Post by: Habib on December 17, 2023, 22:13

Thanks, Jahanzaib. I hope so.

@QuantumATK, is there any alternative to COHP and pCOHP in QuantumATK?

Title: Re: Simulation of COHP and pCOHP
Post by: Anders Blom on January 5, 2024, 21:06

I'm afraid we only have MullikenPopulations, which obviously isn't as advanced. But it depends a bit on the end goal - you could perhaps use ProjectedDensityOfStates if you are looking to see where different orbitals or sites are positioned in energy

Title: Re: Simulation of COHP and pCOHP
Post by: Habib on January 7, 2024, 22:15

Hi Anders,

Thanks for your reply.
I have been attempting to simulate the five 3d orbitals of Fe in LaFeO3—namely, dxy, dxz, dyz, dx2-dy2, and dz2—through spin-polarized DFT+U simulations. I utilized PDOS with the "projections=ProjectOnOrbitalsByElement" setting, and it worked well, producing the DOS of the mentioned orbitals in one spin (refer to the attached file). However, I require both spin-up and spin-down positions. Can you help me to simulate the DOS in both spin?

Title: Re: Simulation of COHP and pCOHP
Post by: Anders Blom on January 19, 2024, 00:21

You can't do that via the GUI for now, but in the script  you can create more complex projections. In your case, open the Python script in an editor and change the value of the "projection" keyword in ProjectedDensityOfStates to

ProjectionGenerator(atoms=ElementsProjection, l_quantum_numbers=True, m_quantum_numbers=True, spin=UpDownProjection)