Chlorophylls - natural solar cells
  A molecular modeling study was conducted on a series of six natural occurring chlorophylls. Quantum chemistry calculated orbital energies were used to estimate frequency of transitions between occupied molecular orbital and unoccupied molecular orbital energy levels of chlorophyll molecules in vivo conditions in standard (ASTMG173) environmental conditions. Obtained results are in good agreement with energies necessary to fix the Magnesium atom by chlorophyll molecules and with occurrence of chlorophylls in living vegetal organisms. 
Lorentz Jantschi, Sorana D. Bolboaca, Mugur C. Balan, Radu E. Sestras
physics.chem-ph physics.bio-ph