Interface uff

This interface offers a partial implementation of the Universal Force Field (UFF)[1], making it possible to carry out simplie calculations in Cuby without any external software. It is useful for testing and demonstration purposes.

The implementation has following limitations:

• Works only for limited set of elements: H,C,N and O
• Atomic charges are estimated using different method[2] that in original UFF

1. J. Am. Chem. Soc. 114(25), 10024, 1992
2. J. Phys. Chem. A, 2002, 106 (34), pp 7887–7894

Methods and capabilities

The interface implements a single unnamed method; 'method' keyword not necessary

The interface implements following atomic charge types (keyword 'atomic_charges'):

• forcefield - Forcefield charges

Keywords used

This interface does not use any specific keywords

Other keywords used by this interface:

• atomic_charges_read
• charge

Examples

The following examples, along with all other files needed to run them, can be found in the directory cuby4/interfaces/uff/examples

#===============================================================================
# UFF example 1 - geoemtry optimization
#===============================================================================

job: optimize

interface: uff

geometry: |
  H    1.967603917  -1.140511213  -0.300259482
  H    3.180209441  -0.153234074  -0.313604159
  H    2.335499457  -0.311642212   0.991150017
  H   -0.619663449  -0.149076101  -1.607628437
  H   -2.638561649  -0.977700792  -0.510855092
  H   -0.330701092   1.595133723   0.115327602
  H   -2.114864632  -0.525222032   0.881866437
  H   -2.539775062   0.542853517  -0.184426700
  H    0.145591691   0.535059473   1.114346776
  C    2.233400000  -0.224500000   0.000200000
  O    1.408500000   0.824800000  -0.435800000
  C    0.114500000   0.699800000   0.128500000
  N   -0.663700000  -0.306000000  -0.621000000
  C   -2.025000000  -0.309300000  -0.090400000