$SURF group              (relevant for RUNTYP=SURFACE)                          
    This group allows you to probe a potential energy                           
surface along a small grid of points.  Note that there is                       
no option to vary angles, only distances.  The scan can                         
be made for any SCFTYP, or for the MP2 or CI surface.  You                      
may specify two rather different calculations to be done                        
at each point on the grid, through the RUNTYPn, SCFTYPn,                        
and electron correlation keywords.                                              
* * * below, 1 and 2 refer to different calculations * * *                      
RUNTP1,RUNTYP2 = some RUNTYP supported in $CONTRL                               
         First RUNTYP=RUNTP1 and then RUNTYP=RUNTP2 will be                     
         performed, for each point on the grid.  The second                     
         run is omitted if RUNTP2 is set to NONE.                               
         default: RUNTP1=ENERGY RUNTP2=NONE                                     
SCFTP1,SCFTP2 = some SCFTYP supported in $CONTRL                                
         default: SCFTYP in $CONTRL                                             
CITYP1,CITYP2 = some  CITYP supported in $CONTRL                                
         default:  CITYP in $CONTRL                                             
MPLEV1,MPLEV2 = some MPLEVL supported in $CONTRL                                
         default: MPLEVL in $CONTRL                                             
CCTYP1,CCTYP2 = some  CCTYP supported in $CONTRL                                
         default:  CCTYP in $CONTRL                                             
DFTYP1,DFTYP2 = some DFTTYP supported in $DFT                                   
         default: DFTTYP in $DFT                                                
You may need to help by giving values in $CONTRL that will                      
permit the program to estimate what is coming in the values                     
here.  For example, if you want to request hessians here,                       
it may be good to give RUNTYP=HESSIAN in $CONTRL so that                        
in its earliest stages of a job, the program can initialize                     
for 2nd derivatives.  There is less checking here than on                       
$CONTRL input, so don't request something impossible such                       
as two correlation methods simultaneously, or analytic                          
hessians for MP2, or other things that are impossible.                          
* * * below, 1 and 2 refer to different coordinates * * *                       
IVEC1  = an array of two atoms, defining a coordinate from                      
         the first atom given, to the second.                                   
IGRP1  = an array specifying a group of atoms, which must                       
         include the second atom given in IVEC1.  The                           
         entire group will be translated (rigidly) along                        
         the vector IVEC1, relative to the first atom                           
         given in IVEC1.                                                        
ORIG1  = starting value of the coordinate, which may be                         
         positive or negative.  Zero corresponds to the                         
         distance given in $DATA.                                               
DISP1  = step size for the coordinate.  If DISP1 is set                         
         to zero, then the keyword GRID1 is read.                               
NDISP1 = number of steps to take for this coordinate.                           
GRID1  = an array of grid points at which to compute the                        
         energy.  This option is an alternative to the                          
         ORIG1, DISP1 input which produces an equidistant                       
         grid.  To use GRID1, one has to set DISP1=0.0.                         
         The number of grid points is given in NDISP1, and                      
         is limited to at most 100 grid points.  The input                      
         of GRID1(1)=ORIG1,ORIG1+DISP1,ORIG1+DISP1*2,...                        
         would reproduce an equidistant grid given by ORIG1                     
         and DISP1.                                                             
     ORIG1, DISP1, and GRID1 should be given in Angstrom.                       
     There are no reasonable defaults for these keywords.                       
IVEC2, IGRP2, ORIG2, DISP2, NDISP2, GRID2 have the same                         
meaning as their "1" counterparts, and permit you to make                       
a two dimensional map along two displacement coordinates.                       
If the "2" data are not input, the surface map proceeds in                      
only one dimension.                                                             

generated on 7/7/2017