Chemistry Reference
In-Depth Information
albumins.
10
The formation of weakly bound heterogeneous clusters plays a key
role in the chemistry of the atmosphere on Earth and elsewhere.
11,12
Noncova-
lent interactions dictate not only the structure and function of biomolecules,
from simple dipeptides to enzymes and DNA,
13-16
but also molecular recogni-
tion events.
17
In the closely related and rapidly growing field of nanotechnology,
highly selective, directional supramolecular self-assembly can be achieved with
the aid of intermolecular hydrogen bonding and
-type interactions.
18,19
Hydro-
gen bonding also affects the chemical shielding, and therefore the electronic
properties, of metal atoms in metalloproteins.
20,21
These weak inter- and intra-
molecular forces are even used to control diastereoselectivity and mediate cata-
lysis in important classes of organic reactions.
22,23
The very existence of the
condensed phase (i.e., solids and liquids) is dependent on the noncovalent inter-
actions between molecules (or atoms), as are phase transitions, liquid structure,
diffusion, crystal structure, and solvation/solutions.
24,25
These ubiquitous inter-
actions have even led to the development and refinement of many cardinal che-
mical concepts such as hydrophilicity and hydrophobicity as well as the very
definition of the chemical bond.
Over the past decade, there have been numerous topics
26-31
and arti-
cles
32-44
reviewing ab initio and density functional theory (DFT) computations
of hydrogen bonding and other weak noncovalent interactions. In fact, the
very first chapter of this entire review series examines basis sets for noncova-
lent interactions between atoms and/or molecules,
45
while a chapter in the sec-
ond volume reviews ab initio methods for hydrogen bonding.
46
Three thematic
issues of
Chemical Reviews
have been dedicated to van der Waals interactions
(Vol. 88, No. 6, 1988; Vol. 94, No. 7, 1994; and Vol. 100, No. 11, 2000).
Two articles in the centennial issue of the
Journal of Physical Chemistry
dis-
cuss weakly bound clusters and solvation.
47,48
It is also worth noting that
p
-
type stacking interactions are very topical at the moment and are the subject
not only of a separate chapter in this volume of
Reviews in Computational
Chemistry
49
but also of a special issue of
Physical Chemistry Chemical Physics
(Vol. 10, No. 19, 2008).
This chapter is intended to serve two very distinct purposes. Readers new
to the subject matter will find a fairly thorough introduction to reliable elec-
tronic structure computations for weakly bound clusters (including a step-by-
step tutorial). For more experienced readers, this chapter also reviews many of
the significant advances made in the field since the turn of the twenty-first cen-
tury, particularly current state-of-the-art benchmark studies. This work also
offers some valuable perspective and will attempt to illustrate the importance
of balancing what is possible with what is practical.
p
Clusters and Weak Noncovalent Interactions
Defining the scope of a chapter for
Reviews in Computational Chemistry
on clusters of molecules (and/or atoms) held together by hydrogen bonding,
