The spring constant for ICE springs. You can use an array of scalars to set a different constant for each connection in ConnectionIndices, or you can use a single scalar to use the same coefficient for all connections.
If the SpringCoeffs array is larger than the ConnectionIndices array, then any overflow is ignored. If it is smaller, the last coefficient in the array is repeated for the remaining connections.
For more about ICE springs, see ICE Springs and Dampers [ICE Particle Simulations].
