• Handles
  
  Handles are strings that dereference to a number or integer index. An example of this is the CALC state variable. When the parser reads 'CALC=SCF', it scans the CALC lookup table for the case-insensitive string that matches 'SCF'. Upon finding a match, the value of CALC is set to the offset of 'SCF' in the table. In this case, CALC is set to 0 (zero) since SCF is the first element. Alternatively, the namelist could have read 'CALC=0' and the effect would be the same.
  
  Some keys take boolean values like 'SYMMETRY=ON' or 'ECP=OFF'. For these cases, the key token may be speficied without a value and the parser will assume the value is 'ON'. Similarly, the negation operator '!' may be used to turn the value token to 'OFF'. An example is 'sym,!ecp' meaning 'SYM=ON,ECP=OFF'.
  
  

  Strings
  
  Strings are character arrays that are treated differently depending on the actual key token they define. There are two types: plain text strings and array strings.
  
  

  • plain text strings
    
    Currently, only the BASIS key token accepts this type. This means the exact case-sensitive value token read in for BASIS is used to find the basis set definition in the GENBAS file.
    
    

    array strings
    
    

    • matrices
      
      The state variables OCCUPATION, IP_SYM, EA_SYM, etc. are entered as matrices loosely defined as irrep-by-spin. This means the parser expects to find 'spin' columns of 'nirrep' rows. The row delimiter is a dash and the column delimiter is a forward slash.
      
      Here are some examples: (4 irreps, 2 spins) 'occ=1-1-2-2/1-1-2-2', (2 irreps, 1 spin) 'ip_sym=1-0', (8 irreps, 3 spin pairs) 'ee_sym=1-1-1-1-0-0-0-0/1-1-1-1-0-0-0-0/1-1-1-1-0-0-0-0'.
      
      For future expansion, negative values may be surrounded by parentheses. Observe: 'future_token=(-1)-(-2)/3-4'.
      
      

      sets
      

      Sets are merely one-dimensional arrays of values. The set delimiters are the same as the matrix ones except that the dash specifies a range of values and the forward slash separates single values. Currently, the only key tokens that accept this type of string are: DROPMO, FD_IRREPS, ESTATE_SYM, QRHF_GEN, QRHF_ORB, and QRHF_SPIN.
      

      Here are some examples: (drop orbitals 1, 2, 3, 10, 11, and 12) 'dropmo=1-3/10-12', (compute frequencies of modes that transform as irreps 1, 3, and 4) 'fd_irreps=1/3/4', (add an electron to the third lowest virtual of irrep 2 and remove an electron from the highest occupied of irrep 4) 'qrhf_gen=2/(-4),qrhf_orb=3/1'.
      
      

      NOTE: This syntax is very different from the previous versions. Some value tokens may be allowed by any version but may mean entirely different things. For example, 'DROPMO=1-31' used to mean dropping orbitals 1 and 31 from the correlated calculation. If that string was parsed by the new xjoda, vtran would attempt to remove every orbital from 1 to 31 from the correlated calculation. Additionally, QRHF_GENERAL would have accepted the value string '2/-4' before, but now negative values must be surrounded by parentheses as seen in '2/(-4)'.
      

  
  

  (long) Integers
  
  Parsing value tokens of integers is fairly straight forward. For example, 'print=1' and 'charge=-1'. Notice, the CHARGE value token is not set off by parentheses. This is because the parser knows the CHARGE state variable only accepts values of type integer.
  

  There is one special state variable that recognizes units appended to the value and that is MEMORY. Recognized units are (b)ytes and (w)ords with SI prefixes (k)ilo, (m)ega, and (g)iga. The scaling factor is 1024, not 1000.
  
  

  Doubles
  
  Although we have this capability, there are no key tokens with values of this type. Examples would be: 'double1=1.', 'double2=-2.d0', 'double3=3.5e-6'.
  
  

#!/bin/sh

cat <<. >ZMAT
envvar test job
H
H 1 R

R=0.7

*ACES2
calc=\${CALC}
basis=\${BASIS}

.

for CALC in scf ccsd
do export CALC
   for BASIS in DZP TZP TZ2P
   do export BASIS
      clean # or other cleaning script
      xaces2 > $CALC.$BASIS.out
   done
done
clean

exit