# Theory

#### Disclaimer: this section is for ANA's developers reference. It does not contain relevant information for the users.

## Spring constant

Adaptations used to calculate cavity **flexibility** from Amber mass-weighted eigenvalues.

where,

*ν*: frequency in units of 1/s*λ^{amber}*: amber eigenvalues in units of 1/cm*c*: speed of light- constants added to adjust
*cm*to*angstroms*and*Kg*to*g*

where,

*ω*: angular frequency in units of 1/s

where,

*λ^{NMA}*: spring constant*k*for a NMA vector*m*: mass (doesn't matter as long as units are correct)