a

absorptance (absorptivity)

A

electron acceptor

c _i

mol dm ^?3

molar concentration of species i

D

electron donor

D _i

cm ² s ^?1

diffusion coefficient of species i

E _ox,RD

V vs. ref.

electrode potential for the reaction Ox + ne ^? ? Rd vs. reference electrode

E

V vs. ref.

standard electrode potential (based on activities)

E _m

V vs. ref.

midpoint electrode potential

G

eV molecule ^?1 or kJ mole ^?1

Gibbs free energy

H

eV molecule ^?1 or kJ mole ^?1

enthalpy

j ^s _?

photons m ^?2s ^?1

spectral photon flux with respect to wavelength

q

C

unsigned charge on electron (1.602 10 ^?19 C)

p

atm or Pa

pressure

T

K

absolute temperature

T

transmittance (transmissivity)

U

eV molecul ^?1 or kJ mol ^?1

internal energy

U _g

eV molecul ^?1 or kJ mol ^?1

bandgap or threshold energy for reaction

V

m ³

volume

V

V

voltage

?

cm ^?1 or m ^?1

optical absorption coefficient

? _?

cm ^?1 or m ^?1

optical absorption coefficient at wavelength ?

? _op

optical dielectric constant

? _s

static dielectric constant

? _PS

photosynthetic energy-storage efficiency

?

nm

wavelength

?

eV molecule ^?1

reorganisation energy (of an electron-transfer reaction)