I am currently calculating spin orbit coupling (SOC) calculations for a system where only one gamma point is required.
SOC calculations require the use of the vasp_ncl executable, which is not optimized for gamma-only calculations. I was wondering whether it is possible to compile a vasp_gam_ncl version of VASP.
Thank you for your help!
compile VASP ncl AND gam
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Re: compile VASP ncl AND gam
There is no vasp_ncl and gam version.
In the vasp_gam the charge can be treated as a real quantity.
For non-collinear spin calculations vasp_ncl, the charge density is treated as a complex quantity.
This is to treat the up-up, up-down, and down-down components of the charge density from which the magnetization can be computed.
As such there can be no gamma-only version for a non-collinear spin.
Or to put it more precisely: the optimizations that can be used for the gamma only version (treat the charge as real and doing complex-to-real FFT) cannot be used in the case of non-collinear spin.
In the vasp_gam the charge can be treated as a real quantity.
For non-collinear spin calculations vasp_ncl, the charge density is treated as a complex quantity.
This is to treat the up-up, up-down, and down-down components of the charge density from which the magnetization can be computed.
As such there can be no gamma-only version for a non-collinear spin.
Or to put it more precisely: the optimizations that can be used for the gamma only version (treat the charge as real and doing complex-to-real FFT) cannot be used in the case of non-collinear spin.
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Re: compile VASP ncl AND gam
Thank you for the clarification!