Chapter 294 - 270: As Expected of My Good Student
"It’s very physical."
When Li Dong uttered those three words.
Wu Kai didn’t speak. He just looked at Li Dong for a long time.
Outside the office, the faint beeping from the lab bench could still be heard.
After a while, Wu Kai let out a soft sigh.
He swallowed the frustration that had caught in his throat at Li Dong’s remark.
He was fond of this kid.
He was well aware of this. After all, Li Dong’s achievements remained at Yan University, remained in Huaxia. To him, Li Dong was a special case.
But fondness was one thing, and professionalism another.
Wu Kai had been in the business of chemical synthesis for nearly thirty years.
He knew the rules of the trade.
This field wasn’t like mathematics.
Mathematics could be worked out on a single sheet of scratch paper.
If you showed me a correct derivation today, I’d be ready to take that single piece of paper and argue with the entire world tomorrow.
Chemistry wasn’t like that.
Analytical chemistry, even less so.
Wu Kai began to speak slowly.
"Li Dong."
"I understood your whole spiel just now."
"Use a real representation for the dipole operator, pin down that pi."
"Use X-ray polarization as a boundary condition to nail down at the source which empty orbital gets excited."
"And finally, let the Gamov factor single out the third shell."
"Your entire framework is elegant."
Wu Kai paused.
"But..."
"Analytical chemistry has never been a field that gets by on elegance."
Li Dong didn’t reply.
He knew Teacher Wu had more to say.
Wu Kai continued.
"You said you want to do forward modeling."
"You want to parameterize the entire X-ERT process measured by that SX-STM from start to finish, using physical quantities."
"Fine."
"But take a look back at the parameters you just mentioned."
"The dipole transition matrix element—we can calculate that... DFT can give a reasonable initial value. Using B3LYP+def2-TZVP for a single iron center gives an error of about fifteen percent. It’s barely usable."
"The symmetry of the unoccupied orbitals—VASP can provide that, and PBE+U can suppress the self-interaction. That’s not a big problem."
"The direction of orbital extension—we can make do with an Au(111) substrate and a vdW-D3 correction."
He stopped there.
"But what about the WKB decay constant, kappa, for the vacuum gap?"
He looked up at Li Dong.
"That kappa is the most critical part of your Gamov factor."
"What is it?"
"It’s the effective potential barrier formed by the tip, the small vacuum gap just below it, and the combination of the Au(111) substrate and the Ligand Field."
"The shape of this effective potential barrier..."
"No one has ever measured it."
"You don’t know, I don’t know, and no one in the world knows."
"The few groups currently working on SX-STM can only provide a kappa derived from a phenomenological fit."
"And what is that fit based on?"
"It’s based on existing inversion results."
Wu Kai sighed and continued.
"Do you understand what that means?"
"You want to use kappa to redo the forward model."
"But the only way to obtain the value of kappa itself right now..."
"...is through inversion."
The room fell silent.
Li Dong was truly stumped.
He glanced at the scratch paper.
After his marathon of derivations that morning, he had mentally filed kappa away as a quantity that "could be calculated from fundamental physics."
He had even assumed that he could just go back, chew through a few books, build the effective potential barrier model for the WKB approximation, and give kappa an *a priori* value.
But Wu Kai had just hit him right where he was most vulnerable.
Experimentalists don’t accept "*a priori*."
And analytical chemists *definitely* don’t accept it.
Wu Kai looked at him and sighed again.
"Li Dong, don’t get me wrong."
"I’m not saying your path is definitely wrong."
"I’m saying that from the Logic of our field..."
He paused.
"It’s too speculative."
"No matter how elegantly you construct your mathematical physics framework, its source is empty."
"In analytical chemistry, if the source is empty, no matter how beautiful the rest is, it’s just a castle in the air."
"This project of ours is supposed to produce an experimental paper that *Nature* and *Science* will send back for three rounds of arguments."
"It’s not something you publish in the *Mathematical Annals* and call it a day after that old fellow Langlands writes a nice review."
Wu Kai lowered his voice slightly.
"In this line of work, you have to draw blood for it to count."
Li Dong slowly nodded.
He was calmer in this moment than he would have expected.
He understood what Teacher Wu was saying.
He silently re-ran every *a priori* step in his head.
𝓯𝓻𝒆𝙚𝒘𝓮𝙗𝓷𝒐𝓿𝙚𝒍.𝙘𝓸𝙢
Dipole matrix element, orbital symmetry, orbital extension...
There were solutions for all of those, but not for kappa.
It was just as Teacher Wu had said. Empty.
Li Dong was silent for a moment.
He didn’t rush to argue.
He had a habit.
When he knew his hand was missing the final card, he wouldn’t force the play.
He’d hold his cards.
"Teacher."
Li Dong finally spoke.
"I admit the point you’ve made."
"As for kappa, I really can’t provide a physically independent source for it right now."
"But I still believe my approach is sound. I will solve the problem you’ve raised. Until I do, I will follow your instructions."
Hearing this, Wu Kai felt a sense of relief.
’The kid actually listens to reason.’
’It’s good to be sharp and ambitious in academia.’
’But if a researcher can’t even listen to a colleague’s reasonable doubts...’
’...then no matter how smart they are, they won’t get far.’
Mendeleev: ???
Madam Curie: ???
Wu Kai was silent for a moment before speaking again.
"Li Dong."
"Professor Lu will be back in a few days."
"After he gets back from the beamline coordination meeting in the Capital City, we’ll meet again."
"For the next few days."
"You’ve already pushed your mathematical inversion so far, and the previous step is a bottleneck for researchers both at home and abroad."
"If you keep trying to force your way through, you’ll probably just hit a wall."
"Don’t."
"Take a break from it."
He paused.
"Since you have this whole physical framework in your head..."
"...then use these next few days to go produce it and show me."
Li Dong was slightly taken aback.
Wu Kai continued.
"Whatever equipment you need, just tell Yan’Er."
"Anything in our group that’s available, or even things that haven’t arrived yet, have her coordinate it for you."
"Get your own hands on it and do the work."
"Then put the data you produce right in front of me."
"By then, Teacher Lu will be back, and the three of us will look at it together."
Wu Kai was speaking very seriously.
"We let the data do the talking."
"In the field of chemistry, that’s the one rule."
"If you can really produce even a tiny sprout of a physical source for your kappa in these next few days..."
"...then I’ll reconsider the direction of this project with you."
"If you can’t."
"Then we can’t just stop our work on the inversion path because of your little intuition."
"So, what do you say?"
Li Dong was actually a little surprised.
His original plan was to simply work on it himself if Professor Wu Kai disagreed.
He had never expected Professor Wu Kai to give him a window of a few days, especially not while the project was in full swing.
Let alone devote the project group’s resources to him.
"Deal."
Li Dong’s answer was crisp.
"Teacher, I’ll give it a try for the next few days."
Wu Kai nodded, then seemed to think of something.
"Oh, right."
He looked at the stack of scratch paper on the desk.
"This stuff of yours."
"Can I take it with me?"
Li Dong paused for a second.
"Of course."
He said it without a second thought, completely unhesitatingly.
After all, this was what he was thinking:
’Take it. It’s a dead end anyway.’
Wu Kai was taken aback for a moment.
Li Dong had agreed too readily.
It actually made Wu Kai himself feel a bit embarrassed.
Putting himself in Li Dong’s shoes...
If this were his own work...
A step that a dozen research groups worldwide had been stuck on for three whole years...
If he had been the one to push past it, he definitely wouldn’t let anyone take it.
At most, he’d show it privately to his closest confidants.
Wu Kai looked at Li Dong..
A string in his heart was gently plucked.
’This kid.’
’Does he see me as his closest confidant?’
’He really is a good student of mine.’