1.. index:: angle_style harmonic 2.. index:: angle_style harmonic/intel 3.. index:: angle_style harmonic/kk 4.. index:: angle_style harmonic/omp 5 6angle_style harmonic command 7============================ 8 9Accelerator Variants: *harmonic/intel*, *harmonic/kk*, *harmonic/omp* 10 11Syntax 12"""""" 13 14.. code-block:: LAMMPS 15 16 angle_style harmonic 17 18Examples 19"""""""" 20 21.. code-block:: LAMMPS 22 23 angle_style harmonic 24 angle_coeff 1 300.0 107.0 25 26Description 27""""""""""" 28 29The *harmonic* angle style uses the potential 30 31.. math:: 32 33 E = K (\theta - \theta_0)^2 34 35where :math:`\theta_0` is the equilibrium value of the angle, and :math:`K` is a 36prefactor. Note that the usual 1/2 factor is included in :math:`K`. 37 38The following coefficients must be defined for each angle type via the 39:doc:`angle_coeff <angle_coeff>` command as in the example above, or in 40the data file or restart files read by the :doc:`read_data <read_data>` 41or :doc:`read_restart <read_restart>` commands: 42 43* :math:`K` (energy) 44* :math:`\theta_0` (degrees) 45 46:math:`\theta_0` is specified in degrees, but LAMMPS converts it to 47radians internally; hence :math:`K` is effectively energy per 48radian\^2. 49 50---------- 51 52.. include:: accel_styles.rst 53 54---------- 55 56Restrictions 57"""""""""""" 58 59This angle style can only be used if LAMMPS was built with the 60MOLECULE package. See the :doc:`Build package <Build_package>` doc 61page for more info. 62 63Related commands 64"""""""""""""""" 65 66:doc:`angle_coeff <angle_coeff>` 67 68Default 69""""""" 70 71none 72