SYMBOL

For more involved calculations, the SYMBOL file is a better place to start, as it allows more control over what cluster does. The SYMBOL file for a completed geometry optimisation of methane is shown below. As with the CLUSTER file shown earlier, the line numbers are for reference only and don't appear in the actual file.

1	LBFGS
2	GGA-PBE*GGA-PBE          (DF TYPE EXCHANGE*CORRELATION)     
3	OLDMESH
4	1    NUMBER OF SYMBOLIC FILES
5	ISYMGEN = INPUT
6	  4  NUMBER OF SYMBOLS IN LIST
7	  2  NUMBER OF NUCLEI
8	1.0  1 1 1
9	1.0  1 1 1
10	  1  CALCULATION SETUP BY ISETUP
11	ALL-CAR001 =        0.000000        0.000000        0.000000 UPO
12	ALL-HYD001 =        1.200000        1.200000        1.200000 UPO
13	ELECTRONS  =        5.000000        5.000000
14	EXTRABASIS = 0
15	  2 NEW CALCULATION CREATED BY UPDATE
16	ALL-CAR001 =        0.000000        0.000000        0.000000 UPO
17	ALL-HYD001 =        1.142265        1.142265        1.142265 UPO
18	ELECTRONS =    5.00000        5.00000    
19	EXTRABASIS =  0 
20	  3 NEW CALCULATION CREATED BY UPDATE
21	ALL-CAR001 =        0.000000        0.000000        0.000000 UPO
22	ALL-HYD001 =        1.195741        1.195741        1.195741 UPO
23	ELECTRONS =    5.00000        5.00000    
24	EXTRABASIS =  0