Corrected comments and README file for new command line arguments

git-svn-id: http://qboxcode.org/svn/qb/trunk@831 cba15fb0-1239-40c8-b417-11db7ca47a34

util/dynmat/README

@@ -31,11 +31,15 @@
 
 4) Run the dynmat program using "force.dat"
 
-   use: dynmat force.dat N mass1 .. massN
-   where N is the number of atoms, mass1 .. massN are the masses (C=12)
-   Note: the mass must be repeated for each atom.
-
-   $ ./dynmat force.dat 6 16 16 1 1 1 1 
+   use: dynmat force.dat Nat1 mass1 [Nat2 mass2] ...
+   where Nat1 is the number of atoms of mass mass1 
+   Nat2 is the number of atoms of mass mass2, etc.
+   The mass parameters are in amu (C=12)
+
+   Example for the water dimer (with oxygen atoms first, hydrogen last)
+   Two oxygen atoms of mass 16, four hydrogen atoms of mass 1
+   Displacements used to compute forces are 0.01 (a.u.)
+   $ ./dynmat force.dat 0.01 2 16 4 1 
 
    The frequencies are printed twice in order of increasing magnitude.
    The first six frequencies should be zero. Deviations from zero give

util/dynmat/dynmat.C

@@ -4,8 +4,12 @@
 // The Qbox output should correspond to a sequence of calculations
 // using symmetric finite displacements for all atoms in the x,y,z directions
 //
-// use: diag input_file
-// input_file: forces from Qbox XML output file (collected with grep)
+// use: dynmat force.dat h Nat1 mass1 [Nat2 mass2] ...
+// input_file: force.dat: forces from Qbox XML output file (collected with grep)
+// h: displacement used in the force calculations (a.u.)
+// Nat1: number of atoms of mass mass1
+// Nat2: (optional) number of atoms of mass mass2
+// (repeat the above for all atomic species)
 
 #include <cassert>
 #include <cstdlib>