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Equation 6 · Part 2 · Comparing the Main Approaches to AI for Science and Medicine

subscript

xix_i
subscript

What this part means

The lower label selects a particular version, component, or indexed member of the quantity. For example, x₀ and xₜ can be values at different positions.

Its job in the formula

A subscript distinguishes a version, component, step, or member of a quantity. It does not automatically mean multiplication.

The passage around this formula

where xix_i is the coordinate of atom i in the experimentally solved structure, x^i\hat{x}_i is the corresponding coordinate in the predicted structure after optimal superposition of the two, and N is the number of atoms compared. This is a statement about the average positional deviation of one predicted, static conformation from one experimentally solved, static conformation. It is not, by construction, a statement about how the molecule moves, how quickly it interconverts between conformations, or what its folding pathway looks like — and that distinction is the entire content of what comes next.

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Learn the underlying idea

A subscript is a label attached below a symbol. It often selects a time step, component, category, or member of a sequence.

Open the illustrated subscripts: which member of a family? guide →

Sources cited in the article section

These citations provide research context; check each source for the exact claim it supports.