%%%%%%%%%%%%%%%  -*-Tex-*-  %%%%%%%%%%%%%%%%%%
% short description of MD++ command
%  calHessian

Compute Hessian matrix by numerical differentiation.
%
The step size in ($\AA$) for numerical differentiation
is specified by {\tt timestep}.
%
Result saved in {\tt hessian.out} in the current directory.
%
If {\tt input[0]=0}, then the entire Hessian matrix is computed.
%
If {\tt input[0]$\neq$0}, then {\tt input[0]=n} specifies the number
of atoms whose corresponding (3) columns in the Hessian matrix will
be computed.  The atom indices are specified in {\tt input[1]},
$\cdots$, {\tt input[n]}.
