Writing a fix to apply a non-linear temperature increment

Here is a list of changes made to the source code:

• These are the existing files that have been modified: fix_nh.cpp and fix_nh.h
• These are the methods that have been modified: constructor, destructor, init(), compute_temp_target(), compute_scalar()
• These are the input parameters: betaTemp, boostV, tempExpScalar
• These are the other quantities introduced: boostStyle, boostVar, boostStr, tempExpFlag
• LAMMPS syntax: fix FIX_NAME GROUP nvt tempExp TSTART TPERIOD BETA BOOST OUTPUT_FLAG (we'll review this syntax later in this section)

In this section, we will write a fix that increments the temperature exponentially per timestep with a Nose-Hoover thermostat in a heated system, where the exponential increment is based on the boost potential applied to the system.

Theory – Exponential temperature increment

In hyperdynamics, a boost potential is applied to an atom to allow it to execute...