chatGPT on StdQM vs RealQM for Chemistry

Below is the response by chatGPT on the prompt: Compare StdQM and RealQM as concerns chemistry. 

Here’s a chemistry-centric comparison that stays close to what chemists actually do, not how QM is usually taught in physics.

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StdQM vs RealQM — as chemistry actually uses QM

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1. What chemistry fundamentally needs from QM

Chemistry asks questions like:

• Which structure is stable?

• What is the ground-state energy?

• What are the reaction barriers?

• Which conformer is lowest?

• Which bonds form or break?

All of these reduce to:

Comparing energies and energy landscapes

That’s the key filter.

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2. StdQM (standard quantum mechanics) in chemistry

What StdQM is

• Hilbert space

• Schrödinger equation

• Operators

• Born’s rule

• Measurement postulates

What chemists actually use from it

In practice, chemistry uses only a subset:

• Electronic Hamiltonian

• Eigenvalue problems

• Ground and excited state energies

• Potential energy surfaces

Born’s rule is rarely operational in core chemical reasoning.

Role of probability in StdQM chemistry

• Mostly appears in:

  • spectroscopy intensities

  • thermal populations

  • rate constants (via statistical mechanics)

• Not in:

  • structure

  • bonding

  • stability

  • reaction energetics

So StdQM in chemistry is already quietly de-probabilized.

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3. RealQM in chemistry

What RealQM emphasizes

• The wave function as a real physical state

• Schrödinger dynamics as deterministic

• Energies as objective properties

• No fundamental role for Born’s rule in defining reality

Why this fits chemistry naturally

Chemistry already treats:

• Ground-state energy → real

• Energy barriers → real

• PES minima → real

• Transition states → real (even if unstable)

RealQM simply takes chemists at their word.

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4. The decisive contrast

Aspect	StdQM (textbook framing)	RealQM (chemistry framing)
Primary focus	Measurement outcomes	Physical states
Role of Born rule	Fundamental	Optional / secondary
Ground state energy	“Measured with prob. 1”	Intrinsic property
PES	Tool derived from QM	Physical energy landscape
Chemistry fit	Indirect, inherited	Direct, native

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5. Where StdQM adds nothing chemically

For the chemical core:

• Bonding

• Structure

• Stability

• Reaction energetics

Born’s rule contributes zero explanatory power.

It only re-enters when chemistry asks ensemble questions:

• rates

• yields

• temperature dependence

Those are thermodynamic overlays, not quantum foundations.

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6. A sharp chemistry-first formulation

StdQM treats chemistry as an application of a measurement theory.
RealQM treats chemistry as what it actually is: the physics of energy landscapes.

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7. Why chemistry quietly supports RealQM

This is why:

• Quantum chemistry works spectacularly well

• Measurement theory is almost never discussed

• Wave functions are treated as real objects

• Energies are treated as objective facts

Chemistry already practices RealQM, even if textbooks still teach StdQM.

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8. Bottom line

$$\boxed{{\displaystyle \text{For chemistry, RealQM is sufficient, natural, and already implicit.}}}$$

StdQM:

• is broader,

• measurement-centered,

• and overqualified for chemistry’s core needs.

RealQM:

• captures exactly what chemistry relies on,

• without conceptual excess baggage.