function p = creadpdb(fname)
Read a protein databank file from fname to a structure p containing
some of the elements below:
p.cellsize = Vector giving the lengths of lattice vectors a, b and c
p.cellangl = Vector giving the lattice angles alpha, beta and gamma
p.sgroup = The full Hermann-Mauguin space group symbol
p.z = Z, number of polymeric chains in a unit cell
p.scalem = Matrix of the transformation to crystallographic coords
p.scalev = Vector of the transformation to crystallographic coords
p.atomname = Names of the atoms in ATOM entries (N x 4 char matrix)
p.aresname = Name of the residue (N x 3 char matrix)
p.aresseq = Residue sequence number (N x 1 matrix)
p.acoord = Coordinates of the atoms in ATOM entries (N x 3 matrix)
p.aoccupancy = Occupancy of the atom (N x 1 matrix)
p.atempfactor = Temperature factor of the atoms (N x 1 matrix)
p.hetname = Names of the heterogen atoms (N x 4 char matrix)
p.hetresname = Name of the heterogen residue (N x 3 char matrix)
p.hetresseq = Heterogen residue sequence number (N x 1 matrix)
p.hetcoord = Coordinates of the heterogen atoms (N x 3 matrix)
p.hetoccupancy = Occupancy of the heterogen atoms (N x 1 matrix)
p.hettempfactor = Temperature factors of the hetatoms (N x 1 matrix)
