First principles investigation of hydrogen isotope effects in [XSO₄–H–SO₄X]⁻ (X = H, K) complexes

Abstract

Hydrogen isotope effects on geometries, total energies, nuclear and electronic wave functions of the [HO₃SO–H–OSO₃H]⁻ and [KO₃SO–H–OSO₃K]⁻ complexes are investigated with the NEO/HF method. This method determines both electronic and nuclear wave function simultaneously. A discussion of the isotope effects is provided and used to explain the hydrogen isotope effects on the phase transition temperatures in hydrogen bonded ferroelectric materials, K₃H(SO₄)₂ and K₃D(SO₄)₂.

Keywords:

• hydrogen bond
• isotope effect
• K₃H(SO₄)₂
• K₃D(SO₄)₂
• Ubbelohde effect
• nuclear electronic orbital

Acknowledgements

We gratefully acknowledge the support of COLCIENCIAS grant RC-219 2008 and UNAL grant No 201010011548. We also thank Dr Maria Tubio for proofreading this manuscript.