Calculation of Vm (Matthew's number or coefficient)
Queen's University Protein Function Discovery
and Department of Biomedical and Molecular Sciences
Molecular Modelling and Crystallographic Computing Facility
Crystallography and Modelling:

Calculation of Vm (Matthew's number or coefficient)

Vm (specific volume) is calculated using the formula:  Vm = V/(n*M), where,
    V = volume of the unit cell,
    n = the number of asymmetric units,
    M = molecular weight of contents of the asymmetric unit

One expects a Vm of between 1.68Å**3/dalton and 3.53Å**3/dalton.

Solvent content is also calculated by:  solvent content = (1 - 1.23/Vm)

a b c alpha beta gamma
molecular mass in each monomer daltons
number of monomers in the asymmetric unit
number of asymmetric units
Hint: if your system involves more than one size of monomer, put the total of all monomers in the mass of monomer box and set the number of monomers to 1.
Volume of the cell: Å**3
Vm Å**3/dalton
Solvent Content
To Do Additional Calculations: Change the appropriate values above and press CALCULATE again.

Last revised: Monday, 23-Apr-2012 14:13:50 EDT