2003-01-20 05:58:50 +08:00
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!
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! Copyright (C) 2001 PWSCF group
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! This file is distributed under the terms of the
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! GNU General Public License. See the file `License'
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! in the root directory of the present distribution,
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! or http://www.gnu.org/copyleft/gpl.txt .
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!
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!
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!-----------------------------------------------------------------------
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2003-02-08 00:04:36 +08:00
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function sumkg (et, nbndx, nbnd, nks, wk, degauss, ngauss, e)
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2003-01-20 05:58:50 +08:00
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!-----------------------------------------------------------------------
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!
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! This function computes the number of states under a given energy e
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!
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!
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use parameters
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2003-02-08 00:04:36 +08:00
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implicit none
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2003-01-20 05:58:50 +08:00
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!
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! First the dummy variables.
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!
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2003-02-08 00:04:36 +08:00
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integer :: nks, nbndx, nbnd, ngauss
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2003-01-20 05:58:50 +08:00
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! input: the total number of K points
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! input: the maximum number of bands
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! input: the number of bands
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! input: the type of smearing
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2003-02-08 00:04:36 +08:00
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real(kind=DP) :: wk (nks), et (nbndx, nks), degauss, sumkg, e
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2003-01-20 05:58:50 +08:00
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! input: the weight of the k points
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!input: the energy eigenvalues
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! input: the smearing function
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! output: the sum of the eigenvalues
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! input: the energy to check
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!
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! the local variables
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!
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2003-02-08 00:04:36 +08:00
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real(kind=DP) :: wgauss, sum1
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2003-01-20 05:58:50 +08:00
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! function which compute the smearing
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! auxiliary function
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2003-02-08 00:04:36 +08:00
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integer :: ik, ibnd
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2003-01-20 05:58:50 +08:00
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! counter on k points
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! counter on the band energy
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!
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2003-02-08 00:04:36 +08:00
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sumkg = 0.d0
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do ik = 1, nks
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sum1 = 0.d0
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do ibnd = 1, nbnd
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sum1 = sum1 + wgauss ( (e-et (ibnd, ik) ) / degauss, ngauss)
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enddo
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sumkg = sumkg + wk (ik) * sum1
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enddo
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2003-02-21 22:57:00 +08:00
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#ifdef __PARA
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2003-02-08 00:04:36 +08:00
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call poolreduce (1, sumkg)
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2003-01-20 05:58:50 +08:00
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#endif
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2003-02-08 00:04:36 +08:00
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return
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2003-01-20 05:58:50 +08:00
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end function sumkg
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