TheAlgorithms/Python · error · ValueError

Acceptor concentration should be positive

Error message

Acceptor concentration should be positive

What it means

Raised by builtin_voltage() when acceptor_conc <= 0 while donor_conc is positive. Na appears in the numerator of ln(Nd*Na/ni^2), so a non-positive acceptor doping makes the logarithm undefined. It is the second check in the ordered chain, so donor_conc must already be > 0 for this specific message to appear.

Source

Thrown at electronics/builtin_voltage.py:44

    ValueError: Acceptor concentration should be positive
    >>> builtin_voltage(donor_conc=1000, acceptor_conc=1000, intrinsic_conc=0)
    Traceback (most recent call last):
      ...
    ValueError: Intrinsic concentration should be positive
    >>> builtin_voltage(donor_conc=1000, acceptor_conc=3000, intrinsic_conc=2000)
    Traceback (most recent call last):
      ...
    ValueError: Donor concentration should be greater than intrinsic concentration
    >>> builtin_voltage(donor_conc=3000, acceptor_conc=1000, intrinsic_conc=2000)
    Traceback (most recent call last):
      ...
    ValueError: Acceptor concentration should be greater than intrinsic concentration
    """

    if donor_conc <= 0:
        raise ValueError("Donor concentration should be positive")
    elif acceptor_conc <= 0:
        raise ValueError("Acceptor concentration should be positive")
    elif intrinsic_conc <= 0:
        raise ValueError("Intrinsic concentration should be positive")
    elif donor_conc <= intrinsic_conc:
        raise ValueError(
            "Donor concentration should be greater than intrinsic concentration"
        )
    elif acceptor_conc <= intrinsic_conc:
        raise ValueError(
            "Acceptor concentration should be greater than intrinsic concentration"
        )
    else:
        return (
            Boltzmann
            * T
            * log((donor_conc * acceptor_conc) / intrinsic_conc**2)
            / physical_constants["electron volt"][0]
        )

View on GitHub (pinned to f5988cc097)

Solutions

1. Supply a positive acceptor concentration (Na > 0, typically 1e14-1e19 cm^-3).
2. Audit both doping parameters together before the call: if nd <= 0 or na <= 0: raise with context.
3. Validate imported data rows and drop/flag rows with non-positive concentrations.

Example fix

# before
builtin_voltage(donor_conc=1e16, acceptor_conc=0.0, intrinsic_conc=1e10)  # ValueError

# after
builtin_voltage(donor_conc=1e16, acceptor_conc=1e15, intrinsic_conc=1e10)

def positive(x: float) -> bool:
    return x > 0

def valid_doping(nd: float, na: float, ni: float) -> bool:
    return nd > 0 and na > 0 and ni > 0

When it happens

Trigger: Calling builtin_voltage(donor_conc=1e16, acceptor_conc=-5, ...) or acceptor_conc=0. If donor_conc is also <= 0, error 254 fires first and this message never appears.

Common situations: Symmetric doping variables where only one was populated; copy-paste parameter lists leaving acceptor_conc at a 0 default; sign errors in data ingestion from measurement files.

Related errors

• Donor concentration should be positive
• Intrinsic concentration should be positive
• Capacitor at index {index} has a negative value!
• Capacitor at index {index} has a negative or zero value!
• Expected a_coeffs to have {self.order + 1} elements for {sel

AI-assisted analysis of TheAlgorithms/Python@f5988cc097 (2026-08-14). Data as JSON: /api/errors/cff63c7df5683191. Report an issue: GitHub.