7.5 Tier 4 experimental reproduction

7.5 Tier 4 experimental reproduction

ID	Activity	Acceptance criterion
VAL-07	Conductance versus salt concentration	Experimental range 0.05–3 M, simulated range 0.005–5 M; agreement with experiment no worse than the source paper's own agreement
VAL-08	I–V response and rectification α(V_b) over ±200 mV	Agreement with experiment no worse than the source paper's own agreement, over the full ±200 mV envelope
VAL-09	Cation transport number t_Na⁺	Agreement with experiment no worse than the source paper's own agreement
VAL-10	Classical PNP-NS ablation	The uncorrected model reproduces the published over-estimation of current, in the same direction and of the same order

Rationale (VAL-08): a ±150 mV envelope would drop the highest-|V| quarter, where rectification is largest and Newton convergence hardest.

Rationale (VAL-10): reproducing the documented failure of the uncorrected model is as diagnostic as reproducing the success of the corrected one.

7.5.1 Analyte force validation targets

The analyte force and PMF capability has a published continuum reference: Huang et al., Angew. Chem. Int. Ed. 61, e202206227 (2022), DOI 10.1002/anie.202206227. That work solved the full ePNP-NS system in COMSOL 5.5, 2D-axisymmetric, with haemoglobin represented as a body of revolution of height 6.7 nm and width 5.8 nm carrying a uniform volumetric charge rho_part = q_Hb/V, scanned over −100 ≤ z ≤ 100 nm, and integrated the force to a PMF.

ID	Activity	Acceptance criterion
VAL-11	Force components against the PlyAB reference	At V_b = +50 mV, q_Hb = −4 e, 300 mM NaCl: F^em and F^hd each of magnitude approximately 10 pN and of opposite sign, F^em directed towards trans and F^hd towards cis
VAL-12	PMF minima	Energy minima recovered at z = −2.5 nm and z = +5.25 nm
VAL-13	Residual current on lumen entry	Simulated residual current falls to approximately 40 % on lumen entry; experimental I_res for HbA is 18.5 ± 0.4 % and 40.2 ± 0.7 %
VAL-14	Electro-osmotic force coefficient, ClyA	F_eo = 9 pN at −50 mV, equivalently 0.178 pN/mV, corresponding to N_eo = 15.5 ± 0.9 e

NOTE: F^em and F^hd nearly cancel, so the accuracy requirement on each integral (NUM-29) is set by the residual rather than by the magnitude of either term.

NOTE: the ACS Nano 2019 trapping work is not a continuum analyte calculation. It uses equilibrium Poisson–Boltzmann in APBS on a coarse-grained bead model with a one-dimensional analytic rate model, and provides no stress-tensor force profile. Detail in knowledge/05-analyte-and-forces/11-correction-continuum-force-computation.md.