We investigate the addition of stiffness to the lattice model of hydrogen-bonded polymers in two and three dimensions. We find that, in contrast to polymers that interact via a homogeneous short-range interaction, the collapse transition is unchanged by any amount of stiffness: this supports the physical argument that hydrogen bonding already introduces an effective stiffness. Contrary to possi...

The structure of ethyl 2-amino-4-tert-butyl-1,3-thiazole-5carboxylate, C10H16N2O2S, (I), and the structure of the 1:1 adduct 6-methylimidazo[2,1-b]thiazole±2-amino-1,3-thiazole (1/1), C6H6N2S C3H4N2S, (II), have been determined. The molecules in (I) associate via a hydrogen-bonded R2(8) dimer consisting of NÐH N interactions, with the hydrogenbonding array additionally involving NÐH O interacti...

Hydrogen-bonded nucleic acids base pairs substantially contribute to the structure and stability of nucleic acids. The study presents reference ab initio structures and interaction energies of selected base pairs with binding energies ranging from -5 to -47 kcal/mol. The molecular structures are obtained using the RI-MP2 (resolution of identity MP2) method with extended cc-pVTZ basis set of ato...

The adsorption of hydrogen-bonded and stacked nucleobase pairs on the hexagonal boron nitride (h-BN) surface was studied by density functional theory and molecular dynamics methods. Eight types of nucleobase pairs (i.e., GG, AA, TT, CC, UU, AT, GC, and AU) were chosen as the adsorbates. The adsorption configurations, interaction energies, and electronic properties of the nucleobase pair on the ...

In the triple helical structure of collagen proposed by RAMACHANDRAN and co-workers1, 2 (see ref. 2 for earlier references), there are two N H . . . 0 hydrogen bonds for every three residues in each chain. In the modification of the RAMACHANDRANKARTHA structure proposed by RICI~ A N D C R I C K a, the three chains are pushed slightly farther apart from their positions in this two-bonded structu...

The influence of small monovalent metal ions on hydrogen bonds of aquo-protein complexes is studied on Li/HCONH2-OH2 as an example. Using results obtained from ab initio calculations with minimal GLO basis sets, the remarkable changes in the hydrogen bond energy and charge distribution, due to metal ion complex formation, are discussed. The metal ion seems to enhance strongly the donor-acceptor...

We present a theoretical study of the structure and dynamics of water–carbon tetrachloride liquid–liquid interface by means of ab initio molecular dynamics simulations. We have studied the density profiles, orientational profiles, hydrogen bond distributions, vibrational power spectra, diffusion, orientational relaxation, hydrogen bond dynamics and vibrational spectral diffusion of bulk and int...