The standard human chemical thermodynamic "dodecabond model" (2007) of human chemical bonding, defining attachment between two humans in terms of enthalpic and entropy ties, shown in the context of a human molecular orbital view. [1][3]

In human chemistry, the human chemical bond, A≡B, is an electromagnetic induced stabilizing, attractive-to-repulsive, field-particle mediated, cohesive force functioning to hold human molecules (people) together into bound-state entities, such as marriage pairs, friendships, work units, and social collectives, etc. [1] Thermodynamically, chemical bonding, human or otherwise, is determined according to free energy interactions. This logic is explained by American-born Canadian biochemist Julie Forman-Kay, in her 1999 article "The 'Dynamics' of the Thermodynamics of Binding", as such: [3]

“Whether two molecules will bind is determined by the free energy change (ΔG) of the interaction, composed of both enthalpic and entropic terms.”

The definition given here by Forman-Kay, to note, is defined in the context of interactions between protein molecules. The first to extrapolate this logic of free energy determined binding to the case of interactions between human molecules, was American chemical engineer Libb Thims in circa 2005, in his evolutionary psychology based dodecabond model (as shown adjacent).

Long-term stable marriages are held together via the Gottman stability ratio. In the basic attachment reaction, between two unacquainted individuals, A and B, a collision will occur, in a time-accelerated sense, and the resultant "bond" that form can have various degrees of attachment strength:

A + B → AB (very strong bond)
A + B → A≡B (strong bond)
A + B → A=B (intermediate bond)
A + B → A-B (weak bond)
A + B → A--B (weaker bond)
A + B → A - - - B (detaching stage bond)

The question then immediately becomes: "how are these human chemical bonding variations (A≡B, A=B, A-B) quantified?" The central answer to this question lies in the understanding of the photon-electron interactions of the outer valence shell electons of the bonded individuals, as is the case with all attachments between molecules.

In this direction, human chemical bonds can be studied and modeled from a number of perspectives, such as an "orbital perspective", i.e. tracking the spatial movements of attached people over time on the surface of the earth, an "exchange force" perspective, in which an exchange of particles, which accompanies the interaction and transmits the force, operates, from a "quantum mechanical" perspective, in which quantum inputs or outputs of energy cause jumps in hierarchy location, or from a psychological perspective, e.g. John Bowlby's attachment theory (1953) or Lewis-Amini-Lannon limbic bonding theory (2000), among other points of view, such as neurochemical operation,

A≡B

"Anthropomorphic View" "Symbol View"

"Field Particle Exchange View"

This basic structure of the human chemical bond, using a male-female perspective, is diagrammed in simple form below, from an energy view perspective: [2]

History
The first to outline the logic of thermodynamic stability of bonding, in the context of free energy changes, it seems, was American physical chemist Gilbert Lewis in 1916. [7]

The earliest views on human bonding can be traced to the early 20th century work of various parent-child psychologists, such as Anna Freud, Melanie Kline, James and Joycle Robertson, John Bowlby, Mary Ainsworth, Marshall Klaus, and John Kennell, among others, who developed theories on "attachment" and "parent-infant bonding". [3]

Views on the neurochemical operation of the human bond, popularizing conceptions such as that oxytocin is the "cuddle chemical", began to emerge after the year 1954, the founding year of the discipline of neurochemistry. [5]

The earlist work on human bonding, viewed such that the human bond is a chemical bond, such as described by American chemical engineer Linus Pauling's 1931 article "The Nature of the Chemical Bond", were done by American chemical engineer Libb Thims, between the years 2001 and 2007, as briefly outlined in the 2005 article "On the Nature of the Human Chemical Bond". [4]

References
1. Thims, Libb. (2007). Human Chemistry (Volume Two), (preview), (ch 13: "Human Chemical Bonding", pgs. 515-560). Morrisville, NC: LuLu.
2. The "energy-view perspective" is modeled on the energy-view perspective of sub-atomic relationships, such as in the structure of a proton or neutron, in which approximately 90% of the mass of the structure is found in the gluon bonds. In the structure of any nucleon, according to Dutch theoretical physicist Martinus Veltman, winner of the 1999 Nobel Prize in physics for in 1999 "for elucidating the quantum structure of electroweak interactions in physics", from his 2003 book Facts and Mysteries in Elementary Particle Physics, most of the mass or "energy", as these are equivalent via Einstein's mass-energy equivalence relation, of sub-atomic particles actually resides within the bonds. In the proton, for instance, which consists of two up quarks and one down quark each connected together via gluon "gab" bonds, 923 MeV of its total mass (938 MeV) resides within the gluon bond. Hence, in colloquial terms, most of the essence of the proton or quark relationship is actually found within the bond.
3. Thims, Libb. (2007). Human Chemistry (Volume Two), (preview), (ch 12: "Bond History and Neurochemistry", pgs. 469-513). Morrisville, NC: LuLu.
4. (a) In late 2001 and early 2002, Libb Thims had originally conceived of the basic human reproduction as: A + B → C, in which A and B are the reactants (the dating pair) and C is the product (a 15-year old child). In this mode of logic, Thims had no conception of a the "AB attachment" or bond (this detail was ignored in early calculations). In late 2002 or early 2003, however, it became apparent to Thims that he was leaving out an important component of the reaction, i.e. the AB bond of the attached couple or married pair. The investigation then began to understand what this “AB bond” means from a chemical point of view or fundamental forces point of view. For at least a half a year or more, the issue remained a puzzle.
(b) On 11/10/03, Thims synthesized the concept of Human Molecular Orbital Theory as based on Hybridized Molecular Orbital Theory of small molecules according to the Schrodinger Equation.
(c) On 05/10/04, Thims formulated the Field Particle Exchange Theory of inter-human molecular bonding as based on QED, QCD, particle physics, evolutionary psychology, and the fundamental particles, which defines human molecules to be bonded electromagnetically via connections of either direct or indirect photon bonds.
(d) Thims, Libb. (2005). “On the Nature of the Human Chemical Bond.” Journal of Human Thermodynamics, Vol. 1, Issue 5 (pg. 36-61) – November (left un-finished)
(e) Nearing the end of 2005, it became apparent to that in order to discuss the nature of the human chemical bond in the correct light, he would have to write up a complete textbook on “human chemistry”. Subsequently, he spent the next 18-months and 14-days doing so. The 824-page, two-volume bookset Human Chemistry was published in September of 2007.
5. Neurochemistry (the science of the chemistry of the nervous system) traces it origin to a series of International Neurochemical Symposia, of which the first symposium volume published in 1954 was titled "Biochemistry of the Developing Nervous System" (source: Basic Neurochemistry, 7th ed, 2006).
6. Forman-Kay, Julie D. (1999). “The ‘Dynamics’ in the Thermodynamics of Binding.” Nature Structure Biology, 6: 1086-87.
7. Lewis, Gilbert. (1916). “The Atom and the Molecule”, Journal of the American Chemical Society, Vol. 38, Jan. pgs. 762-86.