angle_style zero command
angle_style zero nocoeff
angle_style zero angle_style zero nocoeff angle_coeff * angle_coeff * 120.0
Using an angle style of zero means angle forces and energies are not computed, but the geometry of angle triplets is still accessible to other commands.
As an example, the compute angle/local command can be used to compute the theta values for the list of triplets of angle atoms listed in the data file read by the read_data command. If no angle style is defined, this command cannot be used.
The optional nocoeff flag allows to read data files with AngleCoeff section for any angle style. Similarly, any angle_coeff commands will only be checked for the angle type number and the rest ignored.