Excellent theme in area of molecular interaction engineering, it is simple and explained based on ideal gas equation. For example, if there are stronger interactions then the internal pressure increase and partial volume decrease so noted as negative deviation because volume is reduced. If the internal pressure is weakened then the volume expand which is noted as positive deviation as the resultant volume of the sample increases. 

Excess Solution quantities are the relative (or "of mixing") quantity minus the same quantity for an ideal solution. They can be either partial or integral molar quantities.

For partial molar quantities:

The volume is the same as the volume of mixing (ideal partial molar volume of mixing being zero) : ditto for enthalpy.  A positive quantity means the partial molar volume increases upon mixing.  In the case of enthalpy, it means the mixing process from the pure component is endothermic. 

In the case of Gibb's energy, the excess partial molar quantity [adopting the common condition in which the pure component is the reference state] is RTln(activity/mole fraction) or RTln(activity coefficient).  A positive value means the component is more active in solution than would be expected based on its mole fraction in the solution: activity coefficient >1.

In the case of partial molar entropy, a positive value means there are atomistic interactions occurring that raise the state of disorder above that which would be expected based on configuration only.

Excellent theme in area of molecular interaction engineering, it is simple and explained based on ideal gas equation. For example, if there are stronger interactions then the internal pressure increase and partial volume decrease so noted as negative deviation because volume is reduced. If the internal pressure is weakened then the volume expand which is noted as positive deviation as the resultant volume of the sample increases. 

There are so many references available for discuss the excess physico - chemical properties. i am sending one of my research paper for this type of work.

The following book references may be found helpful:

Boris Y. Zaslavsky, "Aqueous Two-Phase Partitioning ─ Physical Chemistry and Bioanalytical Applications", Marcel Dekker, New York, 1995.

Alfred W. Francis, "Liquid-Liquid Equilibriums", Interscience Publishers (John Wiley & Sons), New York and London, 1963.

You may be interested in papers by A B Bhatia and myself on binary mixtures. Copies are available on my RG page.

For volumes, enthalpies, and heat capacities:

Thermodynamics of mixtures involving some linear or cyclic ketones and cyclic ethers. 4. Systems containing 1,3-dioxolane. P. Brocos, Á. Piñeiro, R. Bravo, A. Amigo, A. H. Roux, G. Roux-Desgranges; J. Chem. Eng. Data, 49 (2004), 647-657.

Heat capacities, excess enthalpies and volumes of mixtures containing cyclic ethers. V. Binary systems {1,3-dioxolane + 1-alkanols}. P. Brocos, E. Calvo, Á Piñeiro, R. Bravo, A. Amigo, A. H. Roux, G. Roux-Desgranges; J. Chem. Eng. Data, 44 (1999), 1341-1347.

For refractive indices:

Refractive indices, molar volumes and molar refractions of binary liquid mixtures: concepts and correlations. P. Brocos, Á. Piñeiro, R. Bravo, A. Amigo; Phys. Chem. Chem. Phys., 5 (2003), 550-557.

"Critical review on treatment of refractive indices and related properties in liquid mixtures", in Recent Research Developments in Chemical Engineering, vol. 6, 2005 (ISBN 81-7895-190-8); Transworld Research Network (Kerala, India). P. Brocos, A. Amigo. Chapter 3 (pp. 47-84).

  Excess functions in mixed solvents arise due to differences in the chemistry and geometry of the mixing solvents. The excess physical or chemical property of a binary liquid mixture indicates specific interactions between the mixing solvents. These interactions can be stronger or weaker than those existing between the molecules of the pure solvents thus leading to deviations in ideal behaviour. The sign on the value of the excess property therefore shows the magnitude of deviation from ideality and the strength of the interaction between the unlike solvents relative to the interactions of the molecules of the individual solvents before mixing. Depending on the excess property of interest, the sign on the excess function (positive or negative) can adequately be interpreted. For example positive excess molar volume indicates volume expansion on mixing and thus repulsive interaction of mixing solvents or weaker interactions than the interactions of pure solvents. On the other hand, negative excess volume shows stronger interactions of mixed molecules than individual molecules before mixing.

Entropy: A concept that is not a physical quantity

https://www.researchgate.net/publication/230554936_Entropy_A_concept_that_is_not_a_physical_quantity