Chemical energy calculation

Kollman P A 1993. Free Energy Calculations Applications to Chemical and Bicx hemica] Phenojne. Chemical Reviews 93 23 -2417. 

Buetler T C, A E Mark, R C van Schaik, P R Gerber and W F van Gunsteren 1994. Avoiding Singularities and Numerical Instabilities in Free Energy Calculations Based on Molecular Simulations. Chemical Physics Letters 222 529-539. 

Burger M T, A Armstrong, F Guamieri, D Q McDonald and W C Still 1994. Free Energy Calculations in Molecular Design Predictions by Theory and Reality by Experiment with Enantioselective Podand lonophores. Journal of the American Chemical Society 116 3593-3594. 

Empirical energy functions can fulfill the demands required by computational studies of biochemical and biophysical systems. The mathematical equations in empirical energy functions include relatively simple terms to describe the physical interactions that dictate the structure and dynamic properties of biological molecules. In addition, empirical force fields use atomistic models, in which atoms are the smallest particles in the system rather than the electrons and nuclei used in quantum mechanics. These two simplifications allow for the computational speed required to perform the required number of energy calculations on biomolecules in their environments to be attained, and, more important, via the use of properly optimized parameters in the mathematical models the required chemical accuracy can be achieved. The use of empirical energy functions was initially applied to small organic molecules, where it was referred to as molecular mechanics [4], and more recently to biological systems [2,3]. 

PA Kollman. Free energy calculations Applications to chemical and biochemical phenomena. Chem Rev 93 2395-2417, 1992. 

After examining the film breakdown process, we have another question Once broken, how is the film reformed To answer this question, it is necessary to calculate the formation energy for a passive-film nucleus on the film-free surface. The contribution of chemical energy is newly added to the electrocapillary energy. The total energy is thus given by... 

The units are kJ, appropriate for an energy calculation. The drop in temperature of the calorimeter indicates a heat-absorbing process for the calorimeter, so the chemical system absorbs heat from the calorimeter as the compound dissolves. Thus, a positive q is reasonable. Does the magnitude seem reasonable to you ... 

Hydrogen, a fuel that releases a large amount of chemical energy when it bums, is used as an energy source in fuel cells. Use standard enthalpies of formation to calculate the change in mass that occurs when 1.00 mol of H2 is burned. 

The real energy of ion solvation, af, defined by Eq. (2), expresses the change in ion energy upon its transfer from a gas phase into a solution. Unlike the chemical energy of solvation, psi, the value of the real energy of solvation, also in the standard state, can be calculated from experimental data using the formula, e.g., for the hydration of the cation ... 

One main advantage of such a power source is the direct transformation of the chemical energy of methanol combustion into electrical energy. Hence, the reversible cell potential, can be calculated from the Gibbs energy change, AG, associated with the overall combustion reaction of methanol (1), by the equation ... 

As shown in [30], the maximum achievable efficiency of solar-to-chemical energy conversion (calculated with respect to Gibbs free energy) is ca. 60% for the thermocatalytic method and ca. 30% for the photocatalytic method. 

The surface potential of a solution can be calculated, according to Eq. (10.18), from the dilference between the experimental real energy of solvation of one of the ions and the chemical energy of solvation of the same ion calculated from the theory of ion-dipole interaction. Such calculations lead to a value of -1-0.13 V for the surface potential of water. The positive sign indicates that in the surface layer, the water molecules are oriented with their negative ends away from the bulk. 

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