ACES II User manual version 2.7.0 (PDF) - Quantum Theory Project

the first element. Alternatively, the namelist could have read ‘CALC=0’ and the effectwould be the same.Some keys take switch values (ON and OFF). For these cases, the keyword may bespecified without a value and the parser will assume the value is ‘ON’. Similarly, thenegation operator ‘!’ may be used to turn the value to ‘OFF’. An example is ‘sym,!ecp’meaning ‘SYM=ON,ECP=OFF’.Strings are character arrays that are treated differently depending on the keyword theydefine. There are two types: plain text strings and array strings.plain text strings are only used by the BASIS keyword (currently). The exact, casesensitivevalue string is used to find the basis set definition in GENBAS.array stringsmatrices are used by the keywords OCCUPATION, IP SYM, EA SYM, etc.They are loosely defined as irrep-by-spin. This means the parser expects tofind ‘spin’ columns of ‘nirrep’ rows. The row delimiter is a dash and thecolumn 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’Sets are merely one-dimensional arrays of values. The set delimiters are thesame as the matrix ones except that the dash specifies a range of valuesand the forward slash separates single values. Currently, the only keywordsthat 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 electronfrom the highest occupied of irrep 4: ‘qrhf gen=2/(-4),qrhf orb=3/1’NOTE: This syntax is very different from previous versions. Some valuestrings may be allowed by any version but might mean entirely differentthings. For example, ‘DROPMO=1-31’ used to mean dropping orbitals 135