I was wondering if it is possible to calculate the band structure starting from a RDMFT run.
I tried to run task 20 just after a RDMFT run but what I obtained is the LDA band structure and not the RDMFT one. So I guess is not possible to have RDMFT band structure in the current version of elk.
Do you think it would be easy to implement it? Does the RDMFT run create all the necessary files that task 20 need to calculate the band structure.
Any help would be appreciated.
Sa.sa
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Bandstructure using RDMFT cannot be calculated. You can calculate the DOS.
The problem is the same as in the case of Hartree-Fock; you have Eigen values only for kpoints which are a part of your full-minimisation. Unlike DFT, in HF and RDMFT you do not have a local potential and hence given a density/density-matrix you cannot get Eigen values for any k-point which is not part of your initial set.
Best
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just a quick question regarding the RDMFT dos calculated in elk, do I see it correct that in cotrast to a regular DOS the Fermi energy is not at E=0, when running task 10 after 300 ?
best regards
Michael
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This is correct. The chemcal potential is not at 0 in this case.
What one needs to do is to look at the file called "RDM_DEDN.OUT", in this file are written the derivatives (3rd column) of energy wrt n_i (occupation numbers). For all unpinned n_i the derivative is equal to the chemical potential.
Best
Sangeeta
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Dear All,
I was wondering if it is possible to calculate the band structure starting from a RDMFT run.
I tried to run task 20 just after a RDMFT run but what I obtained is the LDA band structure and not the RDMFT one. So I guess is not possible to have RDMFT band structure in the current version of elk.
Do you think it would be easy to implement it? Does the RDMFT run create all the necessary files that task 20 need to calculate the band structure.
Any help would be appreciated.
Sa.sa
Hi sasa,
Bandstructure using RDMFT cannot be calculated. You can calculate the DOS.
The problem is the same as in the case of Hartree-Fock; you have Eigen values only for kpoints which are a part of your full-minimisation. Unlike DFT, in HF and RDMFT you do not have a local potential and hence given a density/density-matrix you cannot get Eigen values for any k-point which is not part of your initial set.
Best
Dear RDMFT users,
just a quick question regarding the RDMFT dos calculated in elk, do I see it correct that in cotrast to a regular DOS the Fermi energy is not at E=0, when running task 10 after 300 ?
best regards
Michael
Hi Michael,
This is correct. The chemcal potential is not at 0 in this case.
What one needs to do is to look at the file called "RDM_DEDN.OUT", in this file are written the derivatives (3rd column) of energy wrt n_i (occupation numbers). For all unpinned n_i the derivative is equal to the chemical potential.
Best
Sangeeta