Bases

G
atom numbers
HB donors/acceptors
pKas
coordinates
extinction coefficient (260nm)

A
atom numbers
HB donors/acceptors
coordinates
pK=4.2/protonation of N1
extinction coefficient (260nm)

C
atom numbers
HB donors/acceptors
coordinates
pK=4.2/protonation of N3
extinction coefficient (260nm)

T
atom numbers
HB donors/acceptors
coordinates
pK=9.8/deprotonation of N3
extinction coefficient (260nm)

U
atom numbers
HB donors/acceptors
coordinates
pK=9.25/deprotonation of N3
extinction coefficient (260nm)

Macro Mol Structure
Williams page