-----------------------------------------------------------------
----------  BSE code, IntEqp  -----------------------------------
-----------------------------------------------------------------

  Version 1.0	(July, 2011) J. Deslippe, D. A. Strubbe

-----------------------------------------------------------------

Description:

This code takes the eqp_co.dat file from Sigma and
interpolates it from the coarse to the fine grid using wavefunction
projections (to resolve band crossings) and linear interpolation
in the Brillouin zone.

-----------------------------------------------------------------

Required Input:

	inteqp.inp	Input parameters. See example absorption.inp in this directory
			for complete options (noting which sections apply to inteqp).
	WFN_fi		Wavefunctions in unshifted fine grid.
	WFN_co		Wavefunctions on coarse grid.
	eqp_co.dat	A list of quasiparticle energy corrections
			for the bands in WFN_co. 

Optional Input:

        WFNq_fi         Wavefunctions in shifted fine grid
                        (used for valence bands if use_velocity is selected)

Auxiliary Files: (output files from previous runs - used as input to speed up calculation)

	dtmat		Transformation matrices, dcc/dvv use for interpolation
			between coarse and fine grid.  This file must be consistent
			with your bsedmat and bsexmat files and corresponding
			coarse and fine wavefunctions.
			NOTE: the file format for dtmat was changed in BerkeleyGW 1.1.0	(r5961)

-----------------------------------------------------------------

Output Files:

        bandstructure.dat	The GW bandstructure on the fine grid.	
        eqp.dat                 Quasiparticle energy corrections for the bands in WFN_fi.
        eqp_q.dat               Quasiparticle energy corrections for the bands in WFNq_fi (if use_velocity).
        dvmat_norm.dat		The norms of the dvv overlap matrices between the valence 
                        	band k on the fine grid and the closest k-point on the coarse grid
        dcmat_norm.dat		The norms of the dcc overlap matrices between the conduction
                        	band k on the fine grid and the closest k-point on the coarse grid
