Simplify complex density matrix build

In the complex case, it is ok to take the square root of negative
numbers. Therefore, there is no need to check whether or not all
the occupation numbers are non-negative.

CMakeLists.txt

@@ -7,7 +7,7 @@ SET(elsi_URL "http://elsi-interchange.org")
 SET(elsi_EMAIL "elsi-team@duke.edu")
 SET(elsi_LICENSE "BSD 3")
 SET(elsi_DESCRIPTION "Electronic Structure Infrastructure")
-SET(elsi_DATESTAMP "20201104")
+SET(elsi_DATESTAMP "20201105")
 
 ### CMake modules ###
 LIST(APPEND CMAKE_MODULE_PATH ${PROJECT_SOURCE_DIR}/cmake)

README.md

-# ELSI - ELectronic Structure Infrastructure (v2.6.3)
+# ELSI - ELectronic Structure Infrastructure (development)
 
 ## About
 

doc/elsi_manual.tex

@@ -21,7 +21,7 @@
 
 \begin{document}
 % Title
-\title{\includegraphics[scale=0.07]{elsi_logo.png}\\ \vspace{0.5cm} \textbf{ELSI Interface Users' Guide\\ v2.6.3}}
+\title{\includegraphics[scale=0.07]{elsi_logo.png}\\ \vspace{0.5cm} \textbf{ELSI Interface Users' Guide}}
 \author{The ELSI Team\\ \url{https://elsi-interchange.org}}
 \maketitle
 

src/elsi_util.f90

@@ -939,21 +939,9 @@ subroutine elsi_build_dm_edm_cmplx(ph,bh,factor,evec,dm,which)
       alpha = (-1.0_r8,0.0_r8)
    end if
 
-   ! Methfessel-Paxton or energy density matrix may have negative factors
-   if(any(factor < 0.0_r8)) then
-      do i = 1,bh%n_lcol
-         call elsi_get_gid(bh%my_pcol,bh%n_pcol,bh%blk,i,gid)
-
-         if(gid <= ph%n_states_solve) then
-            tmp(:,i) = evec(:,i)*factor(gid)
-         end if
-      end do
-
-      call pzgemm("N","C",ph%n_basis,ph%n_basis,ph%n_states_solve,alpha,tmp,1,&
-           1,bh%desc,evec,1,1,bh%desc,(0.0_r8,0.0_r8),dm,1,1,bh%desc)
-   else if(any(factor > 0.0_r8)) then
+   if(any(factor /= 0.0_r8)) then
       do i = 1,ph%n_states
-         if(factor(i) > 0.0_r8) then
+         if(factor(i) /= 0.0_r8) then
             max_state = i
          end if
       end do
@@ -962,7 +950,7 @@ subroutine elsi_build_dm_edm_cmplx(ph,bh,factor,evec,dm,which)
          call elsi_get_gid(bh%my_pcol,bh%n_pcol,bh%blk,i,gid)
 
          if(gid <= max_state) then
-            tmp(:,i) = evec(:,i)*sqrt(factor(gid))
+            tmp(:,i) = evec(:,i)*sqrt(cmplx(factor(gid),kind=r8))
          end if
       end do