CCL: Gaussian Scan



 Sent to CCL by: Tarmo Tamm [tarmo#%#chem.ut.ee]
 Hi
 Opt will initiate a relaxed scan, the "scan" keyword does a restricted
 scan, these are two different things, consult the manual.
 You need to define the rotatable group in a way that no dihedral is
 fixed in place by the hydrogens of the other group.  Carbon is ok, as
 it is placed on the axis of rotation.
 the following z-matrix will do the trick:
  c
  c   1 cc2
  h   2 hc3        1 hcc3
  h   2 hc4        3 hch4         1 dih4
  h   2 hc5        4 hch5         1 dih5
  h   1 hc6        2 hcc6         4 dih6
  h   1 hc7        6 hch7         2 dih7
  h   1 hc8        6 hch8         7 dih8
 cc2         1.450000
 hc3         1.089000
 hcc3        109.471
 hc4         1.089000
 hch4        109.471
 dih4        109.500
 hc5         1.089000
 hch5        109.471
 dih5        109.000
 hc6         1.089000
 hcc6        109.471
 dih6          0.000  35 10.0
 hc7         1.089000
 hch7        109.471
 dih7        109.000
 hc8         1.089000
 hch8        109.471
 dih8        120.000
 A rotation of 35 times 10 deg each (it will also calculate the 1st
 point)
 Hope it helps
 Tarmo Tamm
 University of Tartu
 On Mar 06, Roger Kevin Robinson r.robinson++imperial.ac.uk wrote:
 > Sent to CCL by: Roger Kevin Robinson [r.robinson : imperial.ac.uk]
 > Hi i tried setting each torsion individualy but unsprisingly it did this
 >
 >     16     -60.000000      23     15.0000
 >     17      60.000000      23     15.0000
 >     18    -180.000000      23     15.0000
 >  A total of  13824 points will be computed.
 >
 > which is nt what i want at all and the same problem is still there.
 >
 > Do I need to use this keyword
 >
 > opt=z-matrix     instead of scan
 >
 > I have tried this and runs through but it seems to calculate more energy
 > values than i was expecting and it doesnt put them in a neat little
 > table like scan does.
 >
 > Any reason why it would do this ?
 >
 > Is there any way of telling a whole group to rotate ?
 >
 > Roger
 >
 >