If set to yes (the default), Octopus will ‘pack’ the wave-functions when operating with them. This might involve some additional copying but makes operations more efficient. See also the related StatesPack variable.
Section Linear Response::Sternheimer
The terms to be considered in the variation of the Hamiltonian. The external potential (V_ext) is always considered. The default is to include also the exchange-correlation and Hartree terms, which fully takes into account local fields. Just hartree gives you the random-phase approximation (RPA). If you want to choose the exchange-correlation kernel, use the variable XCKernel. For kdotp and magnetic em_resp modes, or if TheoryLevel = independent_particles, the value V_ext_only is used and this variable is ignored.
Neither Hartree nor XC potentials included.
The variation of the Hartree potential only.
The exchange-correlation kernel (the variation of the
exchange-correlation potential) only.
Section Calculation Modes::Test
If true, the Vector Potential is enforced to be in Coulomb Gauge. See proof of eq 30 of: https://www.scirp.org/pdf/jmp_2016053115275279.pdf
- The volume points of the system box
- The inner mask for the system box. This region has the thickness of the stencil and it is used to set to zero the longitudinal or transverse field after computing the final divergence or curl (to avoid spikes)
- The surface points of the system box
(Experimental) This variable selects the method used for the treatment of the singularity of the Coulomb potential in Hatree-Fock and hybrid-functional DFT calculations. This shoulbe be only applied for periodic systems and is only used for FFT kernels of the Poisson solvers.
The singularity is replaced by zero.
The general treatment of the singularity, as described in Carrier et al, PRB 75 205126 (2007).
This is the default option
The treatment of the singulariy as described in Gygi and Baldereschi, PRB 34, 4405 (1986).
This is formally valid for cubic systems only.
The divergence in q=0 is treated analytically assuming a spherical Brillouin zone
Default 60 in 3D, 1200 in 1D
Number of k-point used (total number of k-points) is (2*Nk+1)^3) in the numerical integration of the auxiliary function f(q). See PRB 75, 205126 (2007) for more details. Only for HFSingularity=general. Also used in 1D.